How to create a dialog window from a thread?

["Michael Loft" <michael loft dk>]

I'm writing a communications application, where I have a thread 
listening to the serial port. When data arrives, I want the thread to 
create a dialog window, so the user can decide what to do.
The problem is, that when I create the dialog, I only see the frame, 
and gtk hangs. The thread continues to run.

Any suggestions on how to create the dialog would be most 
welcome. I've spent three whole days trying to do this until now.

Michael Loft