I've been doing computers long enough to not immediately jump on ZASS as the culprit, but here's what's happening:
On XP Pro, upgraded from 337 to 462. Heeded all forum warnings, and install went fine--no lockups, no other strange behavior. Was able to reboot, etc. just fine.
Then later--I think it was the same day I upgraded to 462--when I went to shut down for the night, Windows wouldn't shut down. Now, let me be clear here: there were no BSODs, no messages, no other indicators of anything strange happening. I clicked on "Start | Turn off computer | Turn off", the "turn-off" dialog went away like it usually does, I waited for Windows to go thru its shut-down ritual, and... Nothing. Nothing happened. I clicked on "Turn off" again. Still nothing. I waited, thinking a process was busy and might be trying to finish. Still nothing. I opened up Task Manager, and tried to shut down via its "Shut Down" menu. No luck. I looked at all the processes running, organizing them by highest CPU usage first. I watched for awhile. No process was using an undue amount (more than 2-3%, and only intermittently) of CPU time. I waited some more. I clicked "Shut down" some more.
Still nothing. I was able to use mouse and keyboard, even open and close programs, w/no problems. It was like the system simply would not recognize that I had told it to shut down, and continued to act as if I had never requested a shut-down. (I also tried "Restart" as well, but that didn't work either.) Finally had to crash the system by shutting off the computer via its power button.
This was about 3 weeks ago. I've had the computer on several times since then, but, due to the holidays, not every day. The behavior never repeated itself, so I figured it was one of those transient things.
Then, last night, it happened again. Same thing, couldn't get system to recognize shut down command. Tried exact same things as before, and also was still able to use mouse and keyboard, still able to open programs.
I opened Task Manager, started killing processes, thinking that maybe--even tho nothing appeared to be monopolizing the CPU--one of them was hanging it somehow. Nothing worked. I finally had to use the power button to shut it off, like before.
Has anyone else had this behavior happen, especially since installing 462? Since it doesn't happen every time I shut down, I'm loathe to try uninstalling and reinstalling ZASS, especially given what a chore it is to fully clean it off the system. Any ideas?

Operating System:Windows XP Pro
Software Version:7.0
Product Name:ZoneAlarm Internet Security Suite