activeX in a MDI application with Framework 2.0

Hi I have developped an activeX control and I begin to play with Visual Studio 2005. I embedded my activeX control in a mdi child form. I encountered my first problem. When the child form opens, the activeX control does'nt paint. It feels like it loses its parent window. I didn't have that problem with Visual Studio 2003 and the Framework 1.1. Any idea ? thanks