I have had a look at the system mod and in particular system.win32.c and it seems to me that paint messages are just dropped and have no corresponding Max event. My knowledge of C is very limited though so perhaps someone else can confirm this. I don't suppose it would be that difficult to modify for someone who is familiar with C. I can't see it being particularly important functionality to have though. You have the Appsuspended function which tells you if the window has lost focus and i would not have thought it consumed much processor time to just continue flipping?