virtualbox.org

Seeing as VirtualBox won't pass GRE packets I can't use VPN directly in my XP guest.

If I connect the VPN in my host (Ubuntu) my XP guest can't see the internal addresses created by the VPN, is there any way it can?

How about:

http://forums.virtualbox.org/viewtopic. ... 3220#23220

Hi, I've tried that and bridging doesn't work on my wireless card.

Perhaps you can bridge your VPN connection? I don't have any experience with that, but it's worth a shot.