answer:It seems that the ‘battle’ between media industry watchdogs MPAA and RIAA and P2P rages on, but recently a new threat to end users of BitTorrent has reared its ugly head: network-level filtering. According to this NYT article, it is real and being considered industry-wide by the telcos, and specific ISPs (possibly Comcast) have already begun implementing this (possibly explaining your situation). Hardware-based filters are now being implemented at the network level to filter ‘good’ and ‘bad’ BitTorrent traffic. Civil Liberties unions are up in arms about this, but it may be too early to tell what is going to happen (read: it’s likely to get uglier). While the conventional response to changing an IP address would be to “release and renew” your IP address via your gateway/router’s admin software, or by contacting your ISP to ask them to reset the IP (given you have a dynamic host address aka DHCP), I’m not sure this is a viable solution for you if Comcast is in fact one of those ‘key ISPs’ now filtering your encrypted BitTorrent traffic. A quick google using the keywords “ISPs cracking down on Bit Torrent” will yield some interesting info for you…here’s one (though quite old-still relevant) from a BiTorrent user’s blog. So suffice it to say, changing the IP may not be an effective solution, but there are definitely some nuggets of info to consider…it may be time to go shopping for a new ISP?...