No Unity 3D on Dell E6420 that has 'OPTIMUS' graphics feature

This has been a pain. Ubuntu 12.04 64 bits on Dell Latitude E6420 has several graphics issues. The recommended NVIDIA drivers (295.33, 295.53, 295.40 and others) don't work as Unity defaults to 2D when using such drivers. If I dock the computer and use dual monitors, the laptop screen will turn 3/4 black, 1/4 gray vertical bar.

Funny thing, the output of "lspci|grep VGA" shows different rev numbers depending on the driver attempted.

NVIDIA Corporation GF119 [Quadro NVS 4200M] (rev ff)
or
NVIDIA Corporation GF119 [Quadro NVS 4200M] (rev a1)

When going into 'System Settings --> Details --> Graphics', I see 'Driver' next to a blank line, and 'Experience Standard' at the moment. When this setup last worked in a semi-acceptable manner, I saw 'Experience Intel Graphics Standard' or something like that.

The question: what is the recommended set of drivers to install on this model that will bring Unity3D back to a reliable working state?

Output of lspci follows below:
00:00.0 Host bridge: Intel Corporation 2nd Generation Core Processor Family DRAM Controller (rev 09)
 Subsystem: Dell Device 0493
 Flags: bus master, fast devsel, latency 0
 Capabilities: [e0] Vendor Specific Information: Len=0c <?>
 Kernel driver in use: agpgart-intel

00:01.0 PCI bridge: Intel Corporation Xeon E3-1200/2nd Generation Core Processor Family PCI Express Root Port (rev 09) (prog-if 00 [Normal decode])
 Flags: bus master, fast devsel, latency 0
 Bus: primary=00, secondary=01, subordinate=01, sec-latency=0
 I/O behind bridge: 00004000-00004fff
 Memory behind bridge: e4000000-e50fffff
 Prefetchable memory behind bridge: 00000000d0000000-00000000e1ffffff
 Capabilities: [88] Subsystem: Dell Device 0493
 Capabilities: [80] Power Management version 3
 Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
 Capabilities: [a0] Express Root Port (Slot+), MSI 00
 Capabilities: [100] Virtual Channel
 Capabilities: [140] Root Complex Link
 Kernel driver in use: pcieport
 Kernel modules: shpchp

00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) (prog-if 00 [VGA controller])
 Subsystem: Dell Device 0493
 Flags: bus master, fast devsel, latency 0, IRQ 45
 Memory at e5400000 (64-bit, non-prefetchable) [size=4M]
 Memory at c0000000 (64-bit, prefetchable) [size=256M]
 I/O ports at 5000 [size=64]
 Expansion ROM at <unassigned> [disabled]
 Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
 Capabilities: [d0] Power Management version 2
 Capabilities: [a4] PCI Advanced Features
 Kernel driver in use: i915
 Kernel modules: i915

00:16.0 Communication controller: Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #1 (rev 04)
 Subsystem: Dell Device 0493
 Flags: bus master, fast devsel, latency 0, IRQ 46
 Memory at e6eb0000 (64-bit, non-prefetchable) [size=16]
 Capabilities: [50] Power Management version 3
 Capabilities: [8c] MSI: Enable+ Count=1/1 Maskable- 64bit+
 Kernel driver in use: mei
 Kernel modules: mei

00:16.3 Serial controller: Intel Corporation 6 Series/C200 Series Chipset Family KT Controller (rev 04) (prog-if 02 [16550])
 Subsystem: Dell Device 0493
 Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 17
 I/O ports at 50e0 [size=8]
 Memory at e6e90000 (32-bit, non-prefetchable) [size=4K]
 Capabilities: [c8] Power Management version 3
 Capabilities: [d0] MSI: Enable- Count=1/1 Maskable- 64bit+
 Kernel driver in use: serial

00:19.0 Ethernet controller: Intel Corporation 82579LM Gigabit Network Connection (rev 04)
 Subsystem: Dell Device 0493
 Flags: fast devsel, IRQ 20
 Memory at e6e00000 (32-bit, non-prefetchable) [disabled] [size=128K]
 Memory at e6e80000 (32-bit, non-prefetchable) [disabled] [size=4K]
 I/O ports at 5080 [disabled] [size=32]
 Capabilities: [c8] Power Management version 2
 Capabilities: [d0] MSI: Enable- Count=1/1 Maskable- 64bit+
 Capabilities: [e0] PCI Advanced Features
 Kernel driver in use: e1000e
 Kernel modules: e1000e

00:1a.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2 (rev 04) (prog-if 20 [EHCI])
 Subsystem: Dell Device 0493
 Flags: bus master, medium devsel, latency 0, IRQ 16
 Memory at e6e70000 (32-bit, non-prefetchable) [size=1K]
 Capabilities: [50] Power Management version 2
 Capabilities: [58] Debug port: BAR=1 offset=00a0
 Capabilities: [98] PCI Advanced Features
 Kernel driver in use: ehci_hcd

00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller (rev 04)
 Subsystem: Dell Device 0493
 Flags: bus master, fast devsel, latency 0, IRQ 48
 Memory at e6e60000 (64-bit, non-prefetchable) [size=16K]
 Capabilities: [50] Power Management version 2
 Capabilities: [60] MSI: Enable+ Count=1/1 Maskable- 64bit+
 Capabilities: [70] Express Root Complex Integrated Endpoint, MSI 00
 Capabilities: [100] Virtual Channel
 Capabilities: [130] Root Complex Link
 Kernel driver in use: snd_hda_intel
 Kernel modules: snd-hda-intel

00:1c.0 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 1 (rev b4) (prog-if 00 [Normal decode])
 Flags: bus master, fast devsel, latency 0
 Bus: primary=00, secondary=02, subordinate=02, sec-latency=0
 Capabilities: [40] Express Root Port (Slot+), MSI 00
 Capabilities: [80] MSI: Enable- Count=1/1 Maskable- 64bit-
 Capabilities: [90] Subsystem: Dell Device 0493
 Capabilities: [a0] Power Management version 2
 Kernel driver in use: pcieport
 Kernel modules: shpchp

00:1c.1 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 2 (rev b4) (prog-if 00 [Normal decode])
 Flags: bus master, fast devsel, latency 0
 Bus: primary=00, secondary=03, subordinate=03, sec-latency=0
 Memory behind bridge: e6d00000-e6dfffff
 Capabilities: [40] Express Root Port (Slot+), MSI 00
 Capabilities: [80] MSI: Enable- Count=1/1 Maskable- 64bit-
 Capabilities: [90] Subsystem: Dell Device 0493
 Capabilities: [a0] Power Management version 2
 Kernel driver in use: pcieport
 Kernel modules: shpchp

00:1c.2 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 3 (rev b4) (prog-if 00 [Normal decode])
 Flags: bus master, fast devsel, latency 0
 Bus: primary=00, secondary=04, subordinate=09, sec-latency=0
 I/O behind bridge: 00003000-00003fff
 Memory behind bridge: e6200000-e6bfffff
 Prefetchable memory behind bridge: 00000000e2b00000-00000000e34fffff
 Capabilities: [40] Express Root Port (Slot+), MSI 00
 Capabilities: [80] MSI: Enable- Count=1/1 Maskable- 64bit-
 Capabilities: [90] Subsystem: Dell Device 0493
 Capabilities: [a0] Power Management version 2
 Kernel driver in use: pcieport
 Kernel modules: shpchp

00:1c.3 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 4 (rev b4) (prog-if 00 [Normal decode])
 Flags: bus master, fast devsel, latency 0
 Bus: primary=00, secondary=0a, subordinate=0a, sec-latency=0
 I/O behind bridge: 00002000-00002fff
 Memory behind bridge: e5800000-e61fffff
 Prefetchable memory behind bridge: 00000000e2100000-00000000e2afffff
 Capabilities: [40] Express Root Port (Slot+), MSI 00
 Capabilities: [80] MSI: Enable- Count=1/1 Maskable- 64bit-
 Capabilities: [90] Subsystem: Dell Device 0493
 Capabilities: [a0] Power Management version 2
 Kernel driver in use: pcieport
 Kernel modules: shpchp

00:1c.5 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 6 (rev b4) (prog-if 00 [Normal decode])
 Flags: bus master, fast devsel, latency 0
 Bus: primary=00, secondary=0b, subordinate=0b, sec-latency=0
 Memory behind bridge: e6c00000-e6cfffff
 Capabilities: [40] Express Root Port (Slot+), MSI 00
 Capabilities: [80] MSI: Enable- Count=1/1 Maskable- 64bit-
 Capabilities: [90] Subsystem: Dell Device 0493
 Capabilities: [a0] Power Management version 2
 Kernel driver in use: pcieport
 Kernel modules: shpchp

00:1d.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #1 (rev 04) (prog-if 20 [EHCI])
 Subsystem: Dell Device 0493
 Flags: bus master, medium devsel, latency 0, IRQ 17
 Memory at e6e50000 (32-bit, non-prefetchable) [size=1K]
 Capabilities: [50] Power Management version 2
 Capabilities: [58] Debug port: BAR=1 offset=00a0
 Capabilities: [98] PCI Advanced Features
 Kernel driver in use: ehci_hcd

00:1f.0 ISA bridge: Intel Corporation QM67 Express Chipset Family LPC Controller (rev 04)
 Subsystem: Dell Device 0493
 Flags: bus master, medium devsel, latency 0
 Capabilities: [e0] Vendor Specific Information: Len=0c <?>
 Kernel modules: iTCO_wdt

00:1f.2 RAID bus controller: Intel Corporation 82801 Mobile SATA Controller [RAID mode] (rev 04)
 Subsystem: Dell Device 0493
 Flags: bus master, 66MHz, medium devsel, latency 0, IRQ 43
 I/O ports at 50d0 [size=8]
 I/O ports at 50c0 [size=4]
 I/O ports at 50b0 [size=8]
 I/O ports at 50a0 [size=4]
 I/O ports at 5060 [size=32]
 Memory at e6e40000 (32-bit, non-prefetchable) [size=2K]
 Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit-
 Capabilities: [70] Power Management version 3
 Capabilities: [a8] SATA HBA v1.0
 Capabilities: [b0] PCI Advanced Features
 Kernel driver in use: ahci

00:1f.3 SMBus: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller (rev 04)
 Subsystem: Dell Device 0493
 Flags: medium devsel, IRQ 11
 Memory at e6e30000 (64-bit, non-prefetchable) [size=256]
 I/O ports at 5040 [size=32]
 Kernel modules: i2c-i801

01:00.0 VGA compatible controller: NVIDIA Corporation GF119 [Quadro NVS 4200M] (rev a1) (prog-if 00 [VGA controller])
 Subsystem: Dell Device 1493
 Flags: bus master, fast devsel, latency 0, IRQ 16
 Memory at e4000000 (32-bit, non-prefetchable) [size=16M]
 Memory at d0000000 (64-bit, prefetchable) [size=256M]
 Memory at e0000000 (64-bit, prefetchable) [size=32M]
 I/O ports at 4000 [size=128]
 Expansion ROM at e5000000 [disabled] [size=512K]
 Capabilities: [60] Power Management version 3
 Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+
 Capabilities: [78] Express Endpoint, MSI 00
 Capabilities: [b4] Vendor Specific Information: Len=14 <?>
 Capabilities: [100] Virtual Channel
 Capabilities: [128] Power Budgeting <?>
 Capabilities: [600] Vendor Specific Information: ID=0001 Rev=1 Len=024 <?>
 Kernel driver in use: nvidia
 Kernel modules: nvidia_current, nvidia_current_updates, nvidia, nouveau, nvidiafb

01:00.1 Audio device: NVIDIA Corporation HDMI Audio stub (rev ff) (prog-if ff)
 !!! Unknown header type 7f
 Kernel driver in use: snd_hda_intel

03:00.0 Network controller: Intel Corporation Centrino Ultimate-N 6300 (rev 35)
 Subsystem: Intel Corporation Centrino Ultimate-N 6300 3x3 AGN
 Flags: bus master, fast devsel, latency 0, IRQ 47
 Memory at e6d00000 (64-bit, non-prefetchable) [size=8K]
 Capabilities: [c8] Power Management version 3
 Capabilities: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+
 Capabilities: [e0] Express Endpoint, MSI 00
 Capabilities: [100] Advanced Error Reporting
 Capabilities: [140] Device Serial Number 24-77-03-ff-ff-14-05-60
 Kernel driver in use: iwlwifi
 Kernel modules: iwlwifi

0b:00.0 SD Host controller: O2 Micro, Inc. Device 8221 (rev 05) (prog-if 01)
 Subsystem: Dell Device 0493
 Flags: bus master, fast devsel, latency 0, IRQ 17
 Memory at e6c20000 (32-bit, non-prefetchable) [size=512]
 Capabilities: [a0] Power Management version 3
 Capabilities: [48] MSI: Enable- Count=1/1 Maskable+ 64bit+
 Capabilities: [80] Express Endpoint, MSI 00
 Capabilities: [100] Virtual Channel
 Capabilities: [200] Advanced Error Reporting
 Kernel driver in use: sdhci-pci
 Kernel modules: sdhci-pci

0b:00.1 Mass storage controller: O2 Micro, Inc. Device 8231 (rev 03)
 Subsystem: Dell Device 0493
 Flags: bus master, fast devsel, latency 0, IRQ 11
 Memory at e6c10000 (32-bit, non-prefetchable) [size=4K]
 Memory at e6c00000 (32-bit, non-prefetchable) [size=2K]
 Capabilities: [a0] Power Management version 3
 Capabilities: [48] MSI: Enable- Count=1/1 Maskable+ 64bit+
 Capabilities: [80] Express Endpoint, MSI 00
 Capabilities: [100] Virtual Channel
 Capabilities: [200] Advanced Error Reporting