I last used it a week ago, successfully. Flash forward to last night, I fired it up with a new torrent, and it... doesn't want to work at all.
"Downloading from 0 of 0 peers", Torrent Inspector "Peers" tab says 2 leechers, 0 seeders, and no matter how long I leave it it will never get going.
The port is open both in transmission and with canyouseeme.org.
I tried 1.5.0 Beta 2, and still not working. Tried backing out to 1.4.1, 1.4.0, back to 1.3.4... not working.
Tried nuking ~/Library/Preferences/org.m0k.transmisison.plist and ~/Library/Application Support/Transmission, and still doesn't work!'
Tried going through dozens of old torrents I successfully downloaded using Transmission and none of them worked.
So I downloaded the hot new uTorrent for OSX and fired it up with the exact same torrent, and it was done in under a minute.
I want to stick with Transmission since it places Mac ahead of Windows and is actually Open Source. Sadly as long as uTorrent works and Transmission doesn't, I gotta stick with what works.

Any ideas? I'm a very technically saavy user and would love to explore in any way suggested. I even built from source for kicks but don't have the time to dive in to Yet Another Code Base right now to learn it...