What causes extreme input lag?

[Booger]

About once every hour or two, my (work) laptop decides each click is worthy of a 4-5 second pause before proceeding. During the pause, I can click like crazy and all commands will wait for that 4-5 seconds before executing in rapid fire succession. Obviously, this drives one completely nuts. I restart and all is well for another hour or two. Six months ago this happened maybe once or twice a day, so something is definitely amiss.

I defragged, cleaned up temp files, etc. as I figured that would surely cure what ails me. I still have problems though. I'm starting to think it's my lack of video card memory. I'm sure some of you have experienced this before. I've googled and googled to no avail. Nick Burns, the company computer guy, was of no help either. Can I get a little help?

Setup:
Thinkpad T42 w/ 1.7 Pentium M
XP Pro
1gb ram
Docked and connected to Dell 2405FPW via DVI
ATI Mobility Radeon 7500 running the latest Omega Drivers

 

[Mister Natural]

control-alt-delete to task manager and see what's eating up the cpu cycles.