VPN works in Vista, but not XP Pro

We have recently setup VPN on a 2003 SB Server.
I can connect fine through Vista and XP, but in XP, I cannot get access to any of the shared folders.
The settings on both machines are the same, the only difference I see, is that on Vista, the default gateway for for the PPTP connection is 0.0.0.0, whereas on XP, the default gateway is the same as the IP address assigned to the laptop.

Everything works flawlessly on the Vista laptop, which blows my mind...

Someone has to have crossed this bridge before...HELP!

Thanks

Same problem here. Wonder if it's the result of a recent patch ? Not had the problem in the past. Vista works great. New XP SP2 patched laptop connects but no DNS and so can not browse. All very strange and so far no clues from Google.
This is just local accounts, no domain wierdness.