I have a new SQL 2005 reporting services installation and it doesn't work.
Database access works fine.
I've setup a new IIS site, set it to run on port 90. It has the two virtual folders – Reports and ReportServer. I can access ReportServer just fine, but Reports (the report manager) throws HTTP 400 error.
I've changed the URL in rsreportserver.config and RSWebApplication.config but it still throws that error.
Best Answer
Download a copy of Fiddler. Check to make sure that your browser requests are what you think they are. Watch each request, especially the one that generates the HTTP/400. Does that request look good to you? This will give you a base from which to troubleshoot.