.I solved a problem very much like this today, and I was lucky to come across the solution. I searched high and low to find it.
For me, my sound/mouse/video would stutter when my hard drive was accessed sometimes. I had just replaced the motherboard since my last one died. My old motherboard was an Asus P5W/DH and the new one is a P5K. I'm running core2duo 6300, 2GB of ram, and 2 IDE HDD's. Both motherboards have a JMicron HDD controller, and I was sure to update the driver in windows when I put the new mobo in.
The solution came from HERE (I don't want to claim it as my own idea!)
http://club.cdfreaks.com/showthrea [...] ge=2&pp=25
and more specifically, a file from here:
http://www.station-drivers.com/page/jmicron.htm
It's as simple as this: the JMicron driver that was bundled with the P5K installed itself automatically for SATA. I don't have SATA, I have IDE drives. When I downloaded the driver from the above site, it actually asked me if I have SATA or IDE. Once I chose IDE, the problem was INSTANTLY fixed. (also, the "updated" drivers from the ASUS website didn't fix my problem)
I can't tell you how many forums I read to finally get the solution, and there's so many people making so many diagnoses' about temperature levels, graphics card drivers, and so on, and they haven't actually suffered the problem themselves.
And then, when each person solves the problem for themselves, they are then happy, and probably don't bother to let everyone else know how!