When Connected to VPN (L2TP) Automatic Login to Intanet Zone does not work...

We are connecting to a Cisco PIX with the built-in Vista L2TP Protocol.
The Connection works fine and allows access to the Intranet.

When we Connect to the Intranet Website it prompts for a Username and
Password, The Default username that is supplied is the username that is used
to Connect to the VPN.

Is there a way to it to use the Logged on to the machine user vs. the Logged
on to the VPN User?

Thanks,
Scott<-