The two main scenarios where this bug is seen are:
1. Running a VM and pressing the Super key in the VM. This causes the host's Unity dash to open as well as Super being sent to the guest.
2. When the screen is locked (Ctrl+Alt+L), press Super before unlocking the screen with your password. Once unlocked you will notice the Super keypress was received by Unity and the dash was opened before you had even unlocked the screen.
When I use the super key while I'm in kvm with unity 2d and all other actions, including alt + tab, are processed in the vm, when I press the super key, I get the host launcher showing up instead of having the option of using the launcher in the vm.
DistroRelease: Ubuntu 11.04
Package: unity 3.8.16-0ubuntu1~natty1
ProcVersionSignature: Ubuntu 2.6.38-10.44-generic 184.108.40.206
Uname: Linux 2.6.38-10-generic x86_64
Date: Tue Jul 5 18:59:17 2011
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
PATH=(custom, no user)
UpgradeStatus: Upgraded to natty on 2011-04-08 (88 days ago)