I am using WSUS 3.0 SP1 to distribute updates to my network computers. It has always worked great, but after installing a new set of Dell Optiplex 755 machines using Sysprep and Ghost, it seems that only one of the computers shows up at a time in WSUS. Then when the next machine reports its status, it overrides the previous one. In other words, WSUS seems to think that all the computers are the same machine, and is only keeping the status of one of them active.
I've checked the SIDs and the MAC addresses, they are different on each computer. How does WSUS keep track of the computers, and differentiate one from another?