Teleport Issue - Can't TP to 'Southern Continent'

Well, this is irritating.

Since the voice update, I've been unable to return to my home simulator. In fact, I can no longer return to the entire continent my home simulator (Dingo) is located on (the 'southern continent', I guess?). Any attempt on my part to TP to any simulator on the entire continent results in being disconnected completely from SL. Any attempt to log into a simulator on that continent directly from the login page results in a "login packet not received" error.

(It's actually a little more specific than this. I can TP to the eastern half of that continent. The failures begin around the Wollah simulator.)

Amusingly enough, I can TP anywhere else on the grid.

I've detached everything, I've reinstalled, I've blown away the entire SL Application Data folder... I'm at a loss.

Halp?

Ahahahaha, I'm a dork.

I had PeerGuardian running in the background, and it turns out a block of SL simulator IP addresses lay in the block range for the program. Boy do I feel dumb.