I have only gotten one more trace, and that after several hours of testing. That time I got the same error but in another part of the code. I will try to find a pattern,well, there is code after mouse_pos = event_pos.I would add a assert type(event) is not longafter any function call in mouse_button_up to know when event is changed, then drill down the offending function. -- claxo
but I am not hopefull. Bo)