600X hardware problem or Linux problem? Not sure

[yamame]

I'm on the fence about whether this is some kind of hardware issue or a Linux issue, but since things other than Linux exhibit the same problem, I'll try here first and get some other opinions.

The machine: 600X, PIII-500, new 60G/7200 Seagate disk (but does this with the old 20 GB disk, too), 576 meg memory. I hadn't used it in quite a while, so it sat on a shelf with Kubuntu Hoary installed.

Having a need for it once again, I got it off the shelf, booted it up, everything was cool. I popped a Kubuntu Dapper CD in and set out to install. I got as far as "Loading essential drivers" before the machine hung. No combination of boot parms like noapic, apci-off, etc, made any difference. Nor did the Dapper alternate CD, or the Ubuntu server CD. PC BSD showed the same symptoms, as do Win2K and XP install CDs. Knoppix 5.1 also fails to boot. FreeBSD 6.1 will boot successfully but failed to install successfully b/c it got multiple read errors from the CD. They smell like hardware errors to me, but I haven't eliminated the possiblity of a bad image.

However, older Linux distros like Knoppix 3.4, Red Hat 7.3 (I keep the CDs for nostalgia's sake), Kubuntu Hoary, Kubuntu Breezy, will boot. So will a Win98 CD.

So, I installed Breezy, booted from the hard drive, did a dist-upgrade to Dapper, rebooted, and - yup - it hung on boot, at the same place the Dapper installer did.

I rebooted the older Breezy kernel (2.6.12-9) through grub, set it as the default, and booted succesfully.

So, it seems to dislike a 2.6.15 kernel, or anything else that does (I'm theorizing) aggressive hardware probing. Has anyone else encountered this on a 600X? Either way, does this smell like a hardware problem to you? Any ideas on how I can find out exactly what's causing it?

TIA,

Jonathan