I'll be on tonight--though I may be playing from the laptop thus requiring one of you guys to load our save.

I figured out what the issue was on my laptop (obviously). It's running McAfee (due to work rules & regs; v. 8.0 at home and 8.5 on the laptop), and there's a rule enabled by default to disable the common IRC ports. Apparently Civ 4 uses 6667 to process GameSpy ID logins. Also, preexisting GameSpy IDs don't work--only ones created within some version of Civ 4.