Problems launching VirtualBox in headless mode with ssh

I recently installed a VirtualBox image to run remotely using ssh. My command was:

VBoxVRDP -startvm "GuestOS" >~/VBoxVRDP.log 2>&1 &

inside the ssh session.

Whenever closed the ssh session, the virtual machine was killed. I thought it was a problem of the terminal, so I tried out screen and dtach. But the problem was remaining. Googling around, I finally found:

http://www.virtualbox.de/ticket/722

In effect, I had shared clipboard enabled. After I disabled it, I could finally start VirtualBox using:

ssh -x zope@192.168.11.201 'VBoxVRDP -startvm "GuestOS" >~/VBoxVRDP.log 2>&1 &'

Now, I'm a bit happier.
Cheers.