How do i remove a MOUSE_OVER event on CLICK?

Dear gents,
how do i remove a MOUSE_OVER event on CLICK?

when i click on one of my 4 displayed images, the page unloads and is supposed to load another page on a different frame…

During the unload, the mouse pointer hits an image what triggers the MOUSE_OVER event and the unload of the page process stops here…

result… the page with the 4 images is not unloaded, the target page on a different frame does not load and the playhead is at the target frame from the clicked image…

other words… all messed up :frowning:

any ideas?