I'm reactivating this old thread because this just happened to me while I was applying SP1 to my Vista VM.
In the interval since I created the VM on my 6.0.2 workstation, I had added a blue tooth mouse to
the Opensuse Linux 10.3 host and it was working great.
But during the upgrade, Vista discovered the builtin bluetooth adaptor and usurped it right out
from under KDE/Linux. Upon shutting down the Virtual Vista, Linux regained control of the
bluetooth mouse. Rebooting vista did not repeat the problem, and the mouse remained
with the host.
There doesn't even seem to be an option to add a bluetooth device anywhere in the Vmware
settings panel, so why is it possible for Vista (and only vista) to see it directly?
The only think I can think of is that the internal bluetooth radio actually attaches
via the USB bus, and the special install/upgrade shell that vista uses usurped the usb bus
for the duration.
This suggests, that you may want to disconnect the usb controller from the vm
or at least uncheck the automatic connection option when installing vista or
applying SP1 to your vista virtual machines.