Problem with Server 2003 SP1 and VPN

I have Windows 2003 server installed. Networking is wireless. While roaming,
I can VPN to the corporate network and connect to our Exchange server using
Outlook. Once SP1 was installed, Outlook could not find the Exchange server.
Pinging the Exchange box still works. OWA also works. Most of my
administrative snap-in's also fail via VPN. I have a working hosts file for
roaming purposes just to make sure that Outlook can properly resolve to the
remote exchange box.