Drop down menus appear on wrong monitor (dual screens)

I have a problem with the drop down menus in corel photopaint X4. If I right-click in the active screen of the programme, the drop down menu appears on my other monitor, which is very annoying.

Does anybody know how to solve this?

I guess it could be done by changing some numbers in the registry entry for the placement of the menu, but I don't know where to find those entries in the register. So, anyone?

p.s. sorry for the rotated picture, but the site only allows 680x1000 which sucks for a printscreen of two monitors.