I think I had a part in screwing up my fonts a couple of weeks ago. Don’t ask, I’m not sure I could tell you exactly what I did, but I think I managed to duplicate most of my system fonts. I really didn’t notice a problem until I kept seeing strange ligatures in Monaco. Doing what most would do I Googled it. *That’s OK to say in public now ’cause it’s now in the dictionary. :-)*
[LowEndMac] had a nice description of the problem. I was a little wary of trying to fix it because I’m quite certain that messing with Font Book was the reason for my problem. Anyway, some fiddling later and I think I’ve fixed the problem. Time will tell.