Mocking in Forms - Exception handling

Hi,

when testing Forms (e.g. with NUnitForms) I test what happens when users click a button. Ahead I set the expectations. When TypeMock encounters an error (e.g. "Unexpected Call to xxx") it throws an exception. Usually its caught by nunit, but in this case the call stack goes back to the message loop. That means the "Unhandled exception has occured" dialog comes up.
As we have automatic tests running a dialog is what we do not expect.
So I tried AppDomain.CurrentDomain.UnhandledException event catching but it did not work at all as the testing class is not in the initial domain.
Does anybody have an idea how to avoid this exception dialog?
I know this problem is not (only) a typical TypeMock issue but perhaps someone can help me in this forum.

Thanks for any help