Impersonation?

I deployed my website to a productive webserver and am now getting the following error
The request failed with HTTP status 401: Unauthorized. at Microsoft.SqlServer.ReportingServices2005.Execution

 Any idea what's causing this?...I think its failing at a point in the code where I open a reportviewer control and try to read the required parameters in a reporting services report...it doesnt seem to have the access to do this (the reporting services are on a different server).  Everything worked great on the test server, but on this guy I cant seem to get past that point.  I can't really use impersonation becasue I need to know the users identity to give/restrict their access to the site (no login, I just get the windows identity)

Any ideas?
...