DickeFix, I tested your temporary fix of adding the magnet link you specified - for ease of copy/pasting for others I have copied it to PasteBin so the Word step can be skipped:
http://pastebin.com/Mwcxq3ei
Just copy and paste the magnet link from the raw paste data section.
For anyone curious about what you're actually downloading here, it's the Pirate Bay magnet archive (http://piratebay.se/torrent/7016365). Just to reiterate a point made earlier, this problem isn't just affecting magnet links from TPB, it's affecting magnet links from everywhere.
When I initially added the file, it sat at 0 downloaders and seeders like the rest, so I didn't think it worked, however any subsequent magnets I then downloaded seemed to start OK!
Just wondering here, if I edit the properties on this download to limit the upload and download rates to 1KB, it now has an ETA of several weeks, would magnet downloads continue to work while this magnet is downloading or is the cache timeout value you were mentioning something separate?