I only ask about the cable because my boss at the computer shop where I work used to crimp his standard cables correctly but all his reversed cables were wrong.
And the guy that I replaced crimped ALL his network cables wrong. They would work as 10 Mbit, but not 100.
So other than that I can't think of many reasons for it to be slow, the are both 2000 machines, so they won't have the 2000-to-98 network problems. Maybe the network cable runs past some power cables ot TV wires and picks up some interference?