Funny I too have the same problem, also with 2.52, however not on Mac. (Updating this would be a horror here on my Debian (stable) box, since at least the .deb package of 2.7X requires libssl 1.0.0 and that would probably break more than 25 programs relating on 0.9.8 ...nah thanks)
Anyways...that problem is definitely there, and it must be T. related.
My scenario is probably way simpler than some of your guys' ones:
- Started downloading torrent, link was a magnet link (as usual these recent days). Worked perfectly.
- Figured out -OOPS- I don't have enough disk space, so I PAUSED the download, moved Location, and RESUMED the download.
- Now all trackers showed 'Connection error' in red.
- Even after 20 minutes, nothing happened.
[*]- Deleted files already downloaded (weren't much anyway) plus the torrent, then re-imported magnet link.
- Result: Magnetizing...yadayada...stayed at 0.00% for minutes, even though it dl'ed at hyper-speed when I first started it.
- OK. Set 'Randomize network port', restarted client, started from step [*] again, worked a treat.
The fact THAT you have to restart the client everytime you pause magnet-driven downloads (because of the fact that it will NEVER connect to any tracker again after resuming d/l) is clearly a BUG. This simply must not happen, as it annoys the hell out of users.
As a provisorical approach, one could add a button that behaves as if the client was restarted (like 'Initialize all' or something). Because the way it is currently is not acceptable for me.