Transmission

Changing "Randomize port on launch" (from no to yes) seems to have worked for me.

Same problem here.
Just tried to download an Ubuntu magnet-torrent.

This is what happens in Transmission 2.71 on Mac OS 10.8.2, PEX and DHT on!

http://i.imgur.com/LepNM.png

The same file in uTorrent:

http://i.imgur.com/7stwA.png

The difference is kinda big.
This is obvious a problem in ...