David,
There are a couple of things that come to mind. The database itself, although I find that less likely. But, it would be easy to have someone look at the tables, etc.
But, the major thing different between Jon's and your setup is the network. My suggestion to rule out EVERYTHING in your network would be to take a laptop or PC and connect it directly to the computer with AC. You may need a crossover cable rather than a patch cable, (you used to always have to), but today's cables can allow you to use a plan Ethernet patch cable. Or, if you have a small switch lying around you can put it in the middle and take care of that problem if it arises.
If you get two to three second speed each time, you'll have your answer. If it is 20 seconds to a minute, you won't. Well you will know it's not the network.
