The MetaFrame servers sent HTTP headers indicating that an error occurred. 401 Unauthorized

I just installed Presentation Server 3 on our new 2003 Server and when I go to login to the web page I get:

ERROR: The Citrix MetaFrame servers cannot process your request at this time. The MetaFrame servers sent HTTP headers indicating that an error occurred. 401 Unauthorized

I checked IIS settings and they all look ok. I've tried loggin in as me as domain admin as local admin.....still nothing.

I have this installed behind an ISA firewall, but I'm connecting from inside the firewall so I'll tackle that when I get to it. Any ideas?!?!?

Solution: The MetaFrame servers sent HTTP headers indicating that an error occurred. 401 Unauthorized