>I have a projecthook class subclassed from the _base class library. The _base class library is in my project. Anytime I try to build an exe I get the error that "..._base is in use and cannot be recompiled". This error rings a bell from a long time ago. I can't seem to find the solution to this.

In addition to what Doug said, you can close the project and use BUILD EXE command.