did you try to check your fo,ts with apple's fontbook ?
Thank you for your post.
Besides the suggestion from Glitchtracker (Thank you!) to check the font with Apple's Font Book, what font are you using? Although I don't think it is a problem, I just want to make sure there isn't a problem with FileMaker Pro and a specific font in Snow Leopard.
Nice Call! It was a Duplicate Font (Arial). FYI: my Font Book app crashed when trying to "Remove Duplicates", so I had to remove them manually.