Well, I can't find any info about UPnP for your modem either. Doesn't seem to have an internal firewall so that wouldn't be a problem. You could try changing ports but since the default port's not being blocked, I don't really think it'd be much use

I did find this, about Cebridge Cable blocking other apps
http://www.utorrent.com/forum/viewtopic.php?id=4128&p=3

I'd say it's your ISP that's the problem. There's some info here about changing ports here, follow LOTR's advice
http://www.gnutellaforums.com/showth...ernative+ports

Someone else here might be able to help you more