C# DLL's

I thought that my problem was how I was declaring a manifest file.
But now I think I can safely rule this out.

I think the probem lies in the way I am loading the DLL/COM object
that the manifest file references.

The program runs -- sort of. After I embed the manifest file into
the executable. I just cannot step through the code in debug mode.

So I put the manifest file into the list of files that the IDE had
to reference. And then I noticed a big change. Then the executable
that I produced had an error message (that I could ignore and continue
running the program, if I choose to) that said the probem was
with the way I was loading the COM object.

How do I load a DLL into a GUI front-end written in C#. Where
should I look for possible problems?