Windows XP Guest taskbar overlays host taskbar in seamless mode

[Alan]

Environment: Windows XP or Vista host with Windows XP guest.

Summary: When in seamless mode, the windows guest taskbar will overlay the host taskbar making the host hard to use. The steps to recreate this are below.

1. Create an XP VM in VirtualBox 3.2.8 or earlier
2. Start the VM
3. Open an IE browser
4. Switch to seamless mode
5. Close the VM, and elect to save its state
6. Start the VM
7. Lock the screen
8. Wait while the VM restores "behind" the locked screen
9. Unlock the screen. Note that the browser is displayed in seamless mode, but only one task bar is visible.

I was running a single display. When I extended my display into an auxiliary monitor. the symptom I was was that the VirtualBox taskbar and the VM browser came up in the auxiliary monitor rather than the main monitor.