I have found that if I modify the port from/to values (in Deluge's network preferences) and click apply TWICE Deluge will begin using the assigned ports.

Or, if there is no way for me to recover my previous state, is it possible to prevent this from happening again? I don't want to have to recheck 100+ torrents every time the power goes out.

My computer lost power briefly, and after restarting, all of my torrents (100+) are missing from Deluge. I looked in .config/deluge/state and there are 147 files in there, including a bunch of torrent files (some with a corresponding .fastresume file), one torrents.state file, and one torrents.fastr...