Using .NET 1.1 via interop from .Net 2.0

[schaf]

HI NG!
I have converted my Project from .NET 1.1 to .NET 2.0.
In my project I use C++ assemblies via an interop dll.
When I use the old assemblies (old means the same referenced asseblies
as I used for the same project in .NET 1.1)

But if I convert my subproject to .NET 2.0 nad I use this ones, I get
a InvalidCastException: Specified cast not valid:.

Convert.ToBoolean(myInteropObject.AdviseEventSink( this));

Does the convertion of the project to .NET 2.0 change any settings? Or
is it not permitted to pass a .NET 2.0 object as an EventSink ? But
why does it work with the old assemblies?

Do you have hints?

Thanks
Regrads
Marcel