Is network transfer speed limited by MS patch

Yesterday I noticed that my laptop computer network appears to be limited.
The laptop has a 100 Mbps connection to a Vista server with a 1 Gpbs NIC and
switch. The Vista system is a SageTV server and I use the laptop to view
videos using the Sage Client. While tring to view videos my laptop network
speed appears to be limited to just over 2.5 Mbps. I then tested network
transfers between the laptop and Vista server and they also were very slow,
none completed properly. I then installed service pack 3 hoping that would
correct the problem, it did not.
Today I used my backup system which also has a 100 Mbps connection to
determine when the problem occurred. It looks like patch KB947864 kills the
network transfer speed on my backup. Removing the patch on the backup system
correct the problem. It does not have SP3 installed yet. I tried to correct
the laptop by removing that patch, it did not make any difference. The SP3
install could not be removed. I tried going back to previous restore points,
none were successful.
Can anyone verify the patch KB947864 (Cumulative Security Update for
Internet Exployer 7 for windows XP) kills their network speed when connecting
to a Vista system. Anyone know how I can fix the network speed on my laptop?