The feature I'm requesting may exist but doesn't work on my Vista machine:
I usually look at the messages sorted by the message number. When I see an interesting message that's part of a larger thread, I'd like to select one of the messages and then click on the subject header and get the messages sorted by the thread name. However, after I select a message and then click on the subject header, the message thread I'm trying to read has lost focus. I have to scroll all the messages trying to locate the thread I want to read.
Hope this makes sense (it's late and I'm tired.)

Thanks,
Brad