Excuse my ignorance but I thought bitdefender was a spyware utility. If it's a firewall, then it's probably best to disable XP firewall. 2 firewalls running together will potentially cause problems with conflicting.
If that doesn't solve the problem, then forwarding a port might be the only solution. See instructions here
http://www.portforward.com/english/r...0/Limewire.htm which are instructions for the WebSTAR-DPR2320 but should be similar if not identical.
BTW Rogers ISP is known to be p2p bandwidth shaping:
ISP's known to BLOCK or Filter p2p or specifically Limewire