Some good tools to help you hunt down problems like this: Depends (http://www.dependencywalker.com/) - Run against a EXE to see what normal DLL's it depends on. FusLogViewer (http://blogs.msdn.com/junfeng/archive/2004/02/14/72912.aspx) Lets you specifically watch .NET exes as they execute to see what and where they are trying to load.
adam...