VPN Broken

Recently in-place upgraded an NT domain to Server
2003/AD. Still running in interim mode. The domain sits
behind MS Proxy 2 in a different forest. I had a VPN set
up and working perfectly with NT; however, since the
upgrade, it is not working. I get Error 930 - The
authentication server did not respond...when I try to log
on.

Seems like it would be a simple fix, but evidently not
simple enough. Any help would be greatly appreciated.

Jeff Wikle, MCP