HD light almost constantly on

This is on a Thinkpad X30 notebook PC running Simply Mepis 3.4-3.

It has 1 GB of RAM, so I doubt swapping is an issue (top showing "0k used" for Swap).

top also shows 90%+ idle for the most part, Mem used around 430MB with Gaim, Mozilla browser and mail client running (mostly idle).

I set up ksysguard to show graphs for all the "Disk Throughput" nodes, and all have been showing zero for total accesses.

I have only / mounted most of the time this is going on, and its entry does have "noatime" set in fstab.

This joker is running *hot*, and I have no confidence it would last long at all on the battery if I wanted to roam around with it. This is not the way it acts when I have it booted to WinXP, so I don't think it is hardware.

Any ideas?

TIA,
Rokky.