IBM T41 on XP, fresh install. Just started using this machine. If it sits doing nothing for a half hour or hour, the screen will be frozen with no cursor visible, and it does not respond to C/A/D. It will suspend properly if done manually. I thought ram, which can trigger lockups, but memtest ran for 7 hr 40 min with no errors.
The XP is a vanilla install, no IBM stuff on it other than an Ultranav driver and a Thinkpad power management driver. Had a bluescreen today while using it, but hadn't set it not to restart yet so I could not copy the error msg.

I have an identical T41 with the same install that behaves properly, so I do not suspect software. Cleaned the fan blades while changing the wireless card and it spins freely. Haven't looked at the heatpipe radiator yet to see if it's clogged. I wonder about heat being an issue, since this is an older laptop.