Cisco VPN 3000 client, WinXP, wierd problems

Using Cisco VPN client v4.0.2(D) and WinXP SP1+a gazillian patches.
My machine does not respond to PING. Checked the obvious stuff. Had ZoneAlarm shutdown, XP Internet connection firewall off/etc.
(and having problems where once in a while I hit Start-Run or try to launch a program and it takes 15-30 seconds before it seems to do anything -- jury is still out whether this is related to the PING issue.)
Anyway, I've learned recently that the Cisco VPN client includes a firewall feature and has the option to always run it, not just when the VPN is connected. I found this check box in options, unchecked it and bingo - I can PING my machine and use TFTP to upgrade my routers again.
This simple little thing has been driving me crazy. Sometimes that's how it goes.