torrent seeding: clients can't connect

Howdy folks,
I've been having upload problems with uTorrent 1.4 over the last week or so. Downloading works great, with data being both sent and received, but when the torrent switches to seed mode no clients can connect. Occasionally one or two clients will appear to connect, but then they disconnect again in two or three seconds.
Testing the port tells me it's open, and my FreeBSD router machine doesn't seem to have any problems. As it is, I cannot get my ratios up above ~30%, and I hate being forced to be a leecher. I've googled but found little relevant information; most hits are people with download problems. Any clues would be appreciated.

>>1
why the fuck do you evencare about this when downloading works fine?
also use a better torrent client.

>>2
Well, even if I was a total asshole and didn't care about seeding, I've heard some trackers like to blacklist people with bad ratios. This is the first problem I've had with uTorrent, and unless I'm unable to fix it, I'm not going trade the nice small memory footprint for something "better".

Same problem, uTorrent 1.3. But thanks to slow connection i get ratio 1 even before download completed.

nice small memory footprint
Meanwhile you are probably running Windows XP.

I lol'ed.