When you get more comfortable in the VS05 IDE, you will eventually have a need to move around and rename projects. VSIDE is very good at taking care of renaming your references. However, you may rename or move a subproject and all of a sudden your ‘using’ statement cannot find it. You check and recheck, you delete and re-add your reference but you still cannot get it to resolve. Don’t panic, just close and re-open the solution. There seems to be something that gets hung up inside the IDE that does not get completely resolved.