usb passthrough problem

[turdsamich]

I have an ubuntu host windows 7 guest where I connect to the internet using a wireless usb adapter, I also have a Windows Phone that I usb sync and update with Zune through the Windows 7 guest. I have a filter set up and working for the windows phone but whenever I connect the phone in the Windows 7 guest my internet connection gets cut and the Ubuntu host system locks up. Is there anyway to block the guest from having access to the usb wireless adapter to prevent this from happening?