Nothing here is about things to fix, but rather about how impossible to debug event handling in system that runs and relies on very same events.. I had very annoying problem with mouse move handling and processing it correctly, and i finally solved the problem after number of attempts to track down where problem lies in.. So, here is small list of problems i faced: - broken image (image won't start up) , because i send unimplemented message in critical place, thus image simply non-responsible/crashing immediately after startup. Easy to fix (sarcasm) - debugger window spam on every event (because of DNU/other exception). A slightly friendlier problem than above :) - and last one, if you break some event handling/delivery, even if image "behaves" you simply left without events doing what is needed, means you got another form of a broken image, which you cannot use anymore and need to start over and revert the changes you made. - veeeerrrrryyy slow event handling, because of printing every event into transcript , trying to see where the shit lies. - decrypting kilometers long event traces to see what goes where But when things finally start work properly, you feel excited :) -- Best regards, Igor Stasenko.