I recently noticed a problem where Firefox would display the text on a large number of website in bold, italic text. As I first noticed it in Google Reader, I’d assumed there was an errant HTML tag somewhere which was causing anything which followed it to be made italic. A bit of investigation put an end to that particular theory so I figured perhaps there was a problem with the fonts themselves. A quick check using Font Book turned up nothing so I turned to Google.

After finding the correct incantation to find some other people who’d had similar problems, I eventually found a thread describing the exact issue I was having. It seemed that the fonts shipped with Office 2008 were causing the problems. I tried resolving them using Font Book but didn’t make much progress. I ended up moving the “Microsoft” folder which was in the Fonts folder, restarted Firefox and everything was back to normal.

I can only assume there is some kind of conflict or corruption with the font but they appeared fine and passed the validation.