I figured at this point I might as well take the plunge and upgrade to Redhat 8, so I did it, and it was a long and slow process, in part thanks to all of the customizations and Ximian-packages I had installed on top of the OS. I finally finished, though, and rebooted, to have it freeze.
So, valiantly, I booted off the install cd and went into rescue mode and switched it from Grub (where it was freezing) to Lilo, and then rebooted.
Voila! It booted. And then I logged in, or tried to, and watched it sit on the splash screen for 10 minutes. Sigh. I tried a few different things, and then said hell with it, and backed up my home directory and then rebuilt the thing from scratch.
Well, the side effect of having 3 boxes on your desk is having 3 keyboards available; in a fit of stupidity I hit ctrl-alt-delete on the box I was rebuilding and caused it to reboot halfway through the installation process. I started from scratch again, and the installer crashed a third of the way through.
Finally, after hours of this, I did it one last time, and now, triumphant at last, I have a brand new, totally clean install of Redhat 8 on my workstation. And boy, I'm exhausted. What a terribly painful process.