Connect to Exchange via VPN using Vista Beta 2 & Outlook 2007 Beta

When I set up my VPN it appears to work (it says it's connected), but the
when I try to connect Outlook 2007 Beta to my work Exchange Server it does
not connect. I get one of the following errors,

"The connection to the Microsoft Exchange Server is unavailable. Outlook
must be online or connected to complete this action."

"The name cannot be resolved. The connection to the Microsoft Exchange
Server is unavailable. Outlook must be online or connected to complete this
action."

I was able to connect Outlook 2007 Beta on XP Home SP2 with no problems.

Any help would be greatly appreciated. Otherwise everthing else is working
great with both Beta products. Thank you.