Seems like every time it's time to download a patch for World of Warcraft, the crappy P2P downloader has a problem on my machine. Although, yes, I hate the P2P downloader with a passion (P2P essentially murders my VoIP phone line during the download period, and for about an hour or so afterward as poorly updated clients with my IP still listed bang the crap out of my internet connection waiting for an answer - "You were there 30 minutes ago!! Where the hell are you now??") - It's not actually the downloader that's the problem. It's my Linksys router. It's severely lacking in features - it barely skims the surface of the plush functionality of my previous, now defunct, WebRamp device.
For some reason on this particular device, the WRT54GP2, a dual-line VoIP wireless router, Linksys didn't feel that I needed the ability to reserve DHCP IPs for specific MAC addresses so that my 'flagship' machines have a guaranteed address. No problem, just hard code an IP on those machines right? That'd be fine if Charter's DNS servers didn't seem to change every month or so.
Anyways, I figured I'd give this INCREDIBLY poorly documented 'port triggering' crap a run for its money and well, what do you know, it works. Hopefully now it won't matter what IP I have. When the downloader starts requesting connections, the router will automatically set up forwarding to the IP I'm currently using. Greatness.
Here's the configuration for the WoW downloader in case it's of use to anyone: