Unity launcher auto hide fails on screen unlock using "Super+L"

I use a Compaq cq40 running Trusty. If I lock the screen using the "Super+L" hotkey, upon unlocking the unity launcher bar appears on the screen. I'll have to press "Super" key twice to hide it again (Hitting once brings up the dash home, hitting once again hides the launcher). This is not observed if use the "Ctrl+Alt+L" hotkey. The following are the system details:

@Enigma:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 14.04 LTS
Release: 14.04
Codename: trusty

@Enigma:~$ uname -a
Linux Enigma 3.13.0-24-generic #47-Ubuntu SMP Fri May 2 23:31:42 UTC 2014 i686 i686 i686 GNU/Linux

@Enigma:~$ sudo apt-cache policy unity
unity:
  Installed: 7.2.0+14.04.20140423-0ubuntu1.2
  Candidate: 7.2.0+14.04.20140423-0ubuntu1.2
  Version table:
 *** 7.2.0+14.04.20140423-0ubuntu1.2 0
        500 http://in.archive.ubuntu.com/ubuntu/ trusty-updates/main i386 Packages
        500 http://security.ubuntu.com/ubuntu/ trusty-security/main i386 Packages
        100 /var/lib/dpkg/status
     7.2.0+14.04.20140416-0ubuntu1 0
        500 http://in.archive.ubuntu.com/ubuntu/ trusty/main i386 Packages

Auto hide is enabled for unity launcher. Is there a way to resolve this annoying behaviour? Thanks!