VPN and Internet simultaneously

Hi guys,
my company is using BT MobileXpress for remote VPN access to the intranet. The problem is that while it’s running it blocks the Internet.
I’m using Windows XP. I tried adding routes in the routing table with metric 1 to go out on my internet gateway instead of the VPN IP but it doesn’t work. It seems like the software is adding a new route of its own(to the VPN) for every site I’m trying to open…
The client has no settings whatsoever… Any ideas how to “cheat” it?