I might have already mentioned this but one behaviour of the Thread map I find very annoying.

When viewing UT in FireFox 3 I like to use multiple tabs to minimize repetition and back/forward button use. I pretty much always view a Thread Map in a new tab. However, if I want to view one or more messages of that map, they always appear in the first UT tab I have open. There is no indication anything has happened in the thread map page; you have to know the messages have been written to the "first" UT tab.

I'd prefer them to appear in the tab that has the thread map; failing that, I'd like the option to open the messages in yet another tab.

The expected behaviour is definitely to respect the current tab, and not go writing them in another one, and that's the way this function (or, at least, the related but now missing "View all messages" function) used to work. It seems to me you're actually going to some extra effort to cause this annoyance, why not just let the messages get written to the current tab?