Kevin,

>Does this happen with all forms that have this architecture or just some? At the point where you try to instantiate the classes, does SET CLASSLIB contain a reference to the library containing the class that can't be found? I've seen problems before using this approach but they were never consistent...the only way I saw to get around it was to add the library into the main project.

I've experienced the same. I wanted to have the BOs in a separate APP and couldn't get it to work properly when the BOs were dropped on forms. I still have to do further investigation, but it seemed to work on W2K/XP, but not on WIN98. But I'm not absolutely sure about that. SET CLASSLIB was done before creating the forms. However adding an object from an external app file at runtime didn't cause any problems. I will post my future experiences here, so everybody who is interested in this can see what happens.

Armin