>Yes, I've done all that, but the problem is still there!

Well, Vera, it's not a bug ... I can tell you that much, but I'm not sure what else to suggest. Perhaps you added a reference wrong, or misspelled something, like a namespace. Does this happen for any of your subclasses or only a specific one? Try to narrow it down further. Remove or comment out things until you can get a clean compile and then add them back in to see where and when it breaks. That's about all the advice I can give you without seeing your entire application.

~~Bonnie