Each torrent has 12 trackers - I've done this so that my files can be more easily accessed. Today they've just stopped however. I close and open KTorrent - no change. Restart Computer - no change. Complete power off restart of everything including router - no change. I manually go in and try each tracker in turn (via change tracker button under trackers) - my files are not being torrented.

Go back two days and there were dozens of people wanting my files, with dozens more seeding. Now I have 0 (0) seeders and 0 (0) leechers in every single column.

For some udp tracking torrents I have 0 (167563987) seeders and 0 (136549878) leechers. (The numbers differ from torrent to torrent) Huh?

I have a theory that my router may be the problem. I've read something about NAT settings but can't make head nor tail of what it means. Can someone explain what I can do to change my router configs to make uploading torrents easier? My router is a Belkin F1PI242ENau and I've just downloaded the user manual.

Help?

I would check your proxy settings, both in KDE and KT. Maybe you accidently enabled a proxy ?

The Pirate Bay was taken offline, as was all trackers operated by them. The resulting shift in userload to other trackers has caused disruptions in their services as well.

I think TPB's web site is back up, but I think their trackers are still offline.

You could try using the following site see if your torrent has any other trackers that are serving it.
http://www.torrentz.com/

I used to use TPB but have since closed username there and none of my torrents track from TPB any more.

I'm using these:

http://tracker.openbittorrent.com/announce
udp://tracker.openbittorrent.com:80/announce
http://tracker.publicbt.com:80/announce
udp://tracker.publicbt.com:80/announce
http://z6gw6skubmo2pj43.onion:8080/announce
http://z6gw6skubmo2pj43.tor2web.com:8080/announce
http://tracker.torrentbox.com:2710/announce
udp://tracker.torrentbox.com:2710/announce
http://www.h33t.com:3310/announce
http://www.torrent-downloads.to:2710/announce
http://denis.stalker.h3q.com:6969/announce
http://www.sumotracker.com/announce

I knew TPB was closing up but did it just stop its tracking suddenly a few days ago? If so then my issue should be a universal one.

I would check your proxy settings, both in KDE and KT. Maybe you accidently enabled a proxy ?

Don't use KDE any more. Xfce is mine. No change of desktop environment in the last week or so either.

Don't touch proxies at all.

You can upload you torrent here:
http://www.torrenteditor.com/

Once loaded, it will scrape all the trackers listed and report their status. That should give you something definitive to compare to.