Why not event-driven packages in other than the main thread?

[Tor Erik]

Hi,

I've developed an application were I've used Tkinter for the GUI.
When I ran the GUI in another thread than the main, it kept locking
up.
I experienced similar problems with Twisted.

Both of these tools are event-based, so I guess that is the root of the 
problem...

But could anyone tell me why running these in a thread other than the 
main one doesn't work?

regards