... (man, I really need a Christmas-themed icon to post with) and lady_curmudgeon's PC is living once more. I owe points a debt of thanks for, well, pointing me in the right direction. On Friday I had surmised that Curmudgeon's computer might just be utterly unable to cope with SATA-2 (a.k.a. SATA 300, I'm lead to understand). Turns out that I was half right. Her computer's SATA controller can't hack SATA-2. What Points found out was that it also cannot hack the Western Digital hard disks I was buying, unless a custom and non-default jumper setting was put in place on the drive to force it to "OPT1 - 150 MB/s data transfer speed enabled." Since the 80gb drive I got yesterday was, in fact, SATA and not SATA-2 I have no idea what this setting is for. But Points suggested I try it and... sure enough, the disk is finally recognized. So, all hail Points for giving me the clue to solve this wretched puzzle.
I'd also like to take a moment to thank the fine folks at Acronis for making the incredibly awesome Acronis TrueImage software. With TrueImage I not only had a backup of Curmudgeon's dying disk drive (which was very nice to have when I literally blew the magic smoke out of the poor thing) but it also included a "CloneDrive" feature that copied everything off the old disk (including the boot sector) onto a new disk and gracefully resized partitions to deal with the differing capacity of the new drive. That made things go a lot more smoothly.
A big "Blow me" to Western Digital for putting that weirdass feature on their drives, and a "blow me" likewise goes out to Via for having such a freakishly twitchy SATA chipset.
And now I away to do some last-minute Christmas shopping with Mudgeon.