Client out-of-date in Remote Administrator Console

The most recent Windows 2000 client we add to our network is always showing as out-of-date in NOD32. It IS NOT in actuality out-of-date. Generally it shows as last connected date the time of original install, though it is turned on and connected to the network at all times.

We tried many things with one client without success, and then it "magically" always showed as updated, but only AFTER we added another Windows 2000 client, which is the one that now shows as out-of-date. Adding Windows XP SP2 clients is not a problem. Tried suggestions from ESET without success. Netware network.