applets in Unity or menu activities (gnome-shell) does not run when virtualbox run FullScreen

This bug affect both gnome-shell and Unity.
I have two monitors, rigth side I use with VirtualBox (4.1 or opensource, does not matter) and left-size my Ubuntu 11.10 amd64 updated.

To reproduze :
1. Start VirtualBox with guest tools instaled with Windows VM (I try with Windows XP)
2. Put VirtualBox with second monitor (1920x1080)
3. Type Host+F to FullScreen on second monitor
4. Open Windows Explorer
5. Get out with the mouse to a first monitor and try to click in any applet on first monitor, dropdown menu does not show any item (with left or right click), not focused, no menu list, nothing. I try with gnome-shell, and menu Activies does not run too, but gnome-shell-extensions run menu-dropdown normally.
6. Come back to your VM, type Host+F to exit from FullScreen and try to show dropdown menu in applets or gnome-shell activities, they come back.

This bug affect any applet on top bar that need dropdown menu with right-click or left-click.
If you have any applications loaded on first monitor, like firefox, when VirtualBox in Fullscreen mode, you can go to Firefox menu fist, than you can go your applets and see thats run now. So, this bug only appear if you exit (with your mouse moviment) from VirtualBox (on fullscren mode) and go to directy to applets (unity) or activities (gnome-shell).

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: gnome-shell 3.2.1-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-13.22-generic 3.0.6
Uname: Linux 3.0.0-13-generic x86_64
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
Date: Wed Nov 16 10:40:48 2011
InstallationMedia: Hamacker LiveDVD - Release amd64
SourcePackage: gnome-shell
UpgradeStatus: No upgrade log present (probably fresh install)