Zone Transition Crashes

[Vent]

About half the time when I change zones (entering or leaving a cave/house/mine or whatever) my internet connection will crash and I'll have to wait a few minutes for it to come on again, making me unable to do anything online or in the game. It only happens with H&H, otherwise my internet works perfectly fine. It happens on both the default web client and on Pacho's (turning IRC off doesn't stop the crashes, as I've read elsewhere on the forums). Any suggestions? I'm running windows XP.