Hi Zakaria,
> What kind of problems are there with ActiveX controls on forms?
well, you have just experienced one <g>. Because VFP Forms aren't true Windows forms, they sometimes have trouble with getting the ZOrder right when working with activeX controls, so they may display either in front of or behind VFP controls without you being able to control it.
Can you move your combobox to somewhere else so it doesn't clash withteh ActiveX?