Strange UI Actions with an ActiveX control

I recently wrapped a series of functions from the Quicktime 4 SDK to build an ActiveX encoder. One of my methods, Configure, is used to pop up the quicktime UI to reconfigure what compression, streaming, and file hinting options are used. It simply calls the Quicktime functions which cause it to show the user dialog (which doesn't involve the passing of any hwnds). When I test this control in VC 6.0's ActiveX Test container, everything works flawlessly, such as the creation of this configure UI, which accepts clicks just fine, and basically works just fine. However, when I embed it in a VB 6.0 project, and call configure, it properly builds the windows, but none of the UI works. ie, it looks like the window doesn't have focus, clicks on it don't register, and tabbing through the fields on the window causes it to shift between the ok and cancel buttons once, then stops working. What would be different between how Visual Basic wraps an ActiveX control, and how something like the Test Container wraps it, which would allow the the control to have a function UI in one and not the other? More importantly, what could I do to fix it? I suspect it has to do with parenting.
-Sean Ward