Installation: "Prepare disk space" w/ 4 disks = missing "Quit", "Back", and "Forward" buttons

Binary package hint: ubiquity

This was encountered during an attempted installation of Jaunty Alpha 3 from

http://cdimage.ubuntu.com/releases/jaunty/alpha-3/jaunty-desktop-amd64.iso

This computer has four disk drives. When the installation reaches step 5
("Prepare disk space"), the number of disks causes the navigation buttons
"Quit", "Back", and "Forward" to disappear off the bottom of the screen.

To reproduce:

1. Boot from the CD
2. Select language (English in my case), followed by "Install Ubuntu"
3. Read pre-release warning, click Forward
    -- This is "Step 1 of 8"
4. Select language (again, English in my case), click Forward
    -- This is also "Step 1 of 8"
5. Select time zone city (Chicago in my case), click Forward
    -- This is now "Step 3 of 8"; perhaps the last step is numbered incorrectly?
6. Select keyboard layout (default, USA in my case), click Forward
    -- This is "Step 4 of 8"
7. Stare at the "busy" mouse pointer for about five minutes. (!)
8. You are now at the screen titled "Prepare disk space." Note that the
"Quit", "Back", and "Forward" buttons are already half obscured at the
bottom of the screen.
9. Select "Guided - use entire disk." This introduces a new line and the
navigation buttons are no longer visible at all.

This is probably more detail than necessary, but here's a textual
representation of what the installer shows at this point:

Prepare disk space
-----------------------------------------------
How do you want to partition the disk?

Before: (picture)

After: (picture)

o Guided - resize SCSI3 (0,0,0) , partition #1 (sdc) and use freed space
    New partition size: (grayed out boxes here)

o Guided - use entire disk
    o SCSI1 (0,0,0) (sda) - 640.1 GB ATA WDC WD6400AAKS-2
       (warning) This will delete Microsoft Windows 2000 Professional and replace it with Ubuntu 9.04.
    o SCSI2 (0,0,0) (sdb) - 500.1 GB ATA WDC WD5000AAKS-2
    o SCSI3 (0,0,0) (sdc) - 320.1 GB ATA MAXTOR STM332062
    o SCSI3 (0,1,0) (sdd) - 203.9 GB ATA Maxtor 6B200P0

o Guided - use the largest continuous free space

o Manual

(horizontal line)

If I press Alt-B to go back to the keyboard layout, the window is not
resized smaller and the nagivation buttons are still invisible. There does
not seem to be a way to resize the window smaller in the vertical
direction; grabbing the top edge of the window and dragging it downward
has no effect.

Incidentally, in the drop down options for the installer window, there is
an option "Move to Workspace Right". That doesn't seem particularly
helpful (the window vanishes and I don't know how to get it back). :-)

If it matters, the computer is an AMD Athlon 64 3200+ / 1GB / ECS
C51G-M754 using the on-board GeForce 6100 graphics.

Best regards,
Kevin