Ok, here's what just now worked yet again:
Found the nice KDE desktop on the latest fresh boot from cd3.3, only the mouse was dead this time. SO, since I went down there (basement hardware hideaway) to swipe the USB drive from that box, I changed the actual drive hardware present.
Then I went about the reboot of the box, hoping to get the drive to read that cd once again. Ha! Joke's on Bill. Seems removing that drive hardware (scsi-emulated usb drive) FORCED the BIOS to poll the drive devices upon boot, instead of reading saved HW info, thus making the cd drive report what it is, and where it's boot sector is, thus making it readable. This is what the "slam-door" technique is after. Sometimes that works, if the disk-change feature reports back to the BIOS that it IS something new here, not just that it's GOT something new in here. I'd imagine it would boot every time if I disconnected the drive cable each time. But that's just not going to happen.
Removing the USB device apparently resets the BIOS HW table, as would installing a new mass storage device, wherein the BIOS polls each drive and rewrites.
BTW, that's a _2_ meg dram SpeedStar64 ISA card, and it boots X just fine from the CD (well, 8-bit), but not from the HD install. Something fishy here...