UI suggestion: When I create trackerless torrent there is an are-you-sure yes-no dialog. Now when save-as dialog appears at the beginning it's quite strange to first ask where do I want to save it and then ask if-I'm-sure. Maybe you should reverse the order. Maybe you could make it a single dialog that both asks me where to save it and reminds me that I have no trackers specified.
UI bug: I use reverse sorting by 'completed on' column to make recently downloaded torrents appear first in the list. In 3.1RC2 torrents sometimes complete but column remains empty for them like forever. And so they keep hanging above among torrents still being downloaded. 3.0 was ok. update: Also I see number in '#' column for these torrents even though they are in seeding state.