when the CentOS tracker was down, I fired up uTorrent on a Windows box w/ the 5.1 i386 dvd torrent, and it managed to find a few dozen peers in a few minutes...
Still blissful (ignorance is ...), hit me with a clue bat if I'm way off base here.
Now, that makes sense (IIUC the implications of all I've read and what y'all have posted). You had already been successfully connected and acquired the DHT during previous sessions. I can guess that this would be used in place of an (un?)available tracker.
last thing I'd torrented off centos was 5.0 prior to this... Not sure that would have any impact on hooking up with DHT on a different torrent (but, I freely admit, I haven't the vaguest clue how the DHT actually hooks up and finds the initial peers)