I thought I would give this one another shot.

Something happens on the upgrade from 10.6.7 to 10.6.8 to change how fonts render on the screen. It's easily noticeable to my eye. Jagged, odd.

I'm in Firefox now. This text looks fine. But the Finder menu, the Firefox window title, and the titles of folders on the bookmarks bar are all jagged.

I downloaded Font Explorer Pro to handle my fonts. Nice program. No corruption or duplicates. This OS by default installs both a Helvetica Neue .dfont and .ttf, and from what Font Explorer tells me both are always active. Both are necessary for the system. You can find more about that in the 10.6 section at http://www.jklstudios.com/misc/osxfonts.html#requiredfonts

But I don't think it's a font problem. I think it's a font rendering problem. Now the question is what parts of the software or hardware are involved in rendering fonts? And what gets changed when 10.6.8 is installed?

It may be the font smoothing. There doesn't seem to be any in 10.6.8. I played around with the Apperances prefs but I can't detect any visual changes, whether I have smoothing checked or what size I use. Maybe the smoothing is broken.

I have 10.6.7 on a backup Firefire drive. With Beyond Compare, I can compare files on both drives to see what is different. Of course, it will take a while. I've done some tests, and there are so many files I'm not sure which ones are clues. And if I find which ones are different, what then?

I'm going to upload some screenshots when I'm satisfied with what I have.

Beyond Compare also allows me to compare images. Nice program.