Thanks a lot that's very relieving as now I know I didn't do design
mistake by my ignorance ....

But now ... Why Microsoft didnt' allow that? Curious to konw, may be
they allow it in the future and we can use it that way.

To share what I was doing, I was making event sink for exchange, and
they wanted it to be out-process COM component. I wanted to do it in
.NET and to make it out-process I made it COM+ enabled.

The event sink simply notifies a running service so the event sink used
remoting to notify the service.

All this hassle could have been just cut short if I can expose the
event sink as COM from .NET class  hosted in the service :D ....

But I guess I was right ....