Hi. I've got a customer that has recently had his CPU, motherboard, and hard drive upgraded. He does a lot of sound editing for his music business, and has recently started having troubles with the sound being jittery. When this happens, his mouse also starts responding slowly. I installed the via 4-in-1 updates yesterday to correct a IRQ Routing issue he had. I know that jittery response usually indicates an overloaded CPU, so I've told him to turn off all of the stuff running in his systray. I haven't heard whether that's helped or not. I believe he has enough power to do what he's doing, though, without having to shut everything else down.
Also, he's complaining about Scandisk locking up Windows when he tries to run it. It locks up when it gets to the initializing phase. I've seen this recently on two other machines, one which an upgrade to 98 Second Edition fixed. I have tested the RAM, with no problems found. Any thoughts or suggests are appreciated. Here's the stats of his machine:

AMD K6/2-550
Soyo SY-5EH5 Motherboard
2 64MB PC-100 totaling 128MB RAM
10GB and 15GB Hard drives
Sound Blaster Live w/ 5 1/4 bay module
Netgear FA310TX PCI NIC
Trident 9440 PCI Video Card
50X Delta CDROM
HP CDWriter 8100
Windows 98SE

Thanks in advance!!