ActiveX with ie8

I have developed an ActiveX application that works in IE7 (well it worked, I'll explain). After development and testing with both IE7 and FF 3.6.6 and all functions worked without fail.

When attempting to demonstrate app at customer site control would not load (Hangs). Customer using IE8.

I decided to install IE8 to troubleshoot problem. I was also unable to get the control to load on IE 8. I attempted to disable DEP, had no effect.

I un-installed IE8, rebooted and ran IE7. Now the control will not load (hangs) in IE7 as well. App still works in FF.

Any help would be greatly appreciated!

Ian