Heavens, I'd forgotten all about this, it was so long ago. I finally called Adobe, forked over $35 or whatever it was to, as Peter said, reset the Preferences. It's been fine ever since. I took lots of notes so that if it ever happens again, I can reset them myself.
However, thirdrockphoto, did you mean to say, "If the indent is set as a measurement, the proportion of indent will NOT change if the font size is changed. I'm intrigued by this, but it doesn't quite make sense, even though it has nothing to do with the problem I was having. >Where< would I set an indent for a certain number of characters?
Thanks!