Hi everyone! I've been investigating this bug ( http://dev.haiku-os.org/ticket/1308 ) for the last two hours, and I'm stuck at the moment. As I've written in that bug's comment, that snippet doesn't count the windows of the application. Therefore I've put several printf-s into _WindowAt in Application.cpp to trace what's happening. (I know it's a caveman method, but that's all I could think of now) Here's what it shows after starting People, creating 2 new windows, and closing one of them: http://bayimg.com/hAEeMaaBO So for some reason the dynamic_cast fails. I've checked, TPeopleWindow inherits from BWindow. So the cast should work. Or isn't the first looper returned by gLooperList the first window? What's happening here? Where should I look now? Thanks, Zsolt