weird XP networking issue

[pvn]

I have an XP machine that has been in storage for about six months.

I booted it up and the networking is foobard.

I can see websites fine (firefox or IE). Gaim/skype work fine.

Thunderbird won't connect to mail servers. I tried three different known working servers, both on the regular imap port and the secure port.

The windows built-in NTP time client does not work.

The VNC server (realvnc 4.1.1 IIRC) will not accept incoming connections, but I can connect it to a listening viewer.

The windows firewall is not the problem, I disabled it.

I also tried resetting winsock with no change (netsh winsock reset).

Any ideas?