I've had the same problem every now and again. I've seen some pretty strange charts myself! :D
You probably have too many fonts in your fonts folder ( c:windowsfonts ).If you're a fontaholic (like I am ;) ) then you've probably added a bunch of fonts there.Get too many and Windows doesn't know what to do with it.UFT seems to have more of an issue with this than other programs.
You can solve this by clearing out fonts you don't really use (you can make another folder and transfer them there) or back them up on a zip disk.A font manager might also help, but isn't necessary.I don't know the magic number for how many fonts you can "safely" have before UFT starts to do strange things.