SQL 2005 Developer Edition (32 bit).
First issue is with the compatibility check-list - namely IIS and ASP.Net
This KB article outlines which features need to be turned on Vista in order for Reporting Services to work.
This link describes how to fix ASP.Net by running following:
cscript %SystemDrive%\inetpub\AdminScripts\adsutil.vbs set w3svc/AppPools/Enable32bitAppOnWin64 1