I am not sure how this occured, I did not reply to this thread.
I use the report viewer and I feed the report parameters. I am building a web page that will have a dynamic menu and dynamic report viewer.
I gave up on attempting to send a user's credentials from the IIS server hosting a web page to the Report server. ( try that one on the fourm world. so many items where a person says Dynamic and people answer with a static solution or the one where someone suggests using Bacis Auth. no! )
However I realized all I needed to do was pass the user id to the report parameters and that works fine.
I do not need to log on to the data base, since that issue is taken care on the Report Server side.
I hope you resolve your issue.
P.S. I still use Crystal reports for Incident reporting. Crystal is used by Heat ( FrontRange ) and LanDesk.