In the wee hours of this morning, I got an idea (which often is a sign of impending doom). I've been using the same windows manager for some time now and I thought I would try out some different ones. I downloaded three of 'em and, after trying each one out, I decided the one I'm using ain't so bad!
After trying the third one, I rebooted my computer to go back to the default -- Gnome. But a funny thing happened when I rebooted: nothing. The GRUB bootloader kept freezing up. It froze up so quickly that it quit loading BEFORE I could get to rescue mode.
Aaah! Now what am I going to do? Fortunately, I have live cds of two different versions of Linux Mint. By this point, I had surmised that the last windows manager I had tried had somehow screwed things up. So, my plan was to load Linux Mint via my cd drive, then find the offending files and delete them.
It seemed like a sensible and reasonable plan...except it didn't work!! Since I signed in to each session as a guest, I didn't have root privileges and, without those privileges, I couldn't delete the files!
I was very fortunate that I had recently downloaded the latest version of Puppy Linux (the distro I had used back when I first switched to Linux). Since Puppy runs solely in RAM, I was able to finagle root status (though I can't remember how I did it) which allowed me to find the offending files and delete them.
Holding my breath, I rebooted and it worked like a charm. My system was back to normal. In order not to have to go through this again, I created a GRUB rescue CD -- something I had put off doing.
This was one of those times when it was quite beneficial to be OCD, though going off to bed at 5:30 am is a bit late...even for a night owl like me :-D