When I compile to PPA a PPT 97 project, my ErrorHandler class throws an automation error when I call Err.Raise from it's public procedure. In the IDE, when I set break in Class Module, I get the same behavior. With error trapping set to Break on Unhandled errors in the IDE, I get the behavior I want. That is, Err.Raise raises an error in the calling procedure.
If I'm running the compiled PPA and I go into the IDE and set the Error Trapping option to Unhandled errors, I get the correct behavior. Needless to say, users should not be required to do this.