Two of my favorite features in Thunderbird are opening messages in separate windows (so that I can see multiple messages at the same time) and threading. But after the last Thunderbird update, I'm finding a conflict: If I double-click on a message that happens to be the top message in a thread, it opens a new message window (as desired), but also collapses the thread (not desired). I can't think of an scenario in which this would be a useful coupling of functions. Am I missing something? By the way, it was already possible to toggle expansion of a thread with a single click on the chevron, so why also trigger this same function with double-clicking?