I've had the same problem since last weekend, and changing the server didn't help, so I don't think that's it. (I'm using the default selection, I believe: "Random US DALnet server.")
What do u mean by connect to another network - via a different ISP? (As u can tell, I'm an IRC newbie.) I'm still suspicious that this has something to do with the upgrade to XP, or at least my reinstallation of mIRC, since that's when mIRC seemed to break on me.
