First, note that this error is normal when there is actually a corrupt font. Use Suitcase Fusion or Font Doctor to diagnose/fix/remove any single corrupted font.
However, if the problem happens for all fonts when a Microsoft app loads, (i.e., it shows the error again and again for every font in the system), this symptom has been observed to appear when Apples font caches are corrupted. Use Font Finagler to remove the Apple cache files.
One interesting point about the symptom is that the MS app was showing errors on fonts that were already removed, so this was a clue to the fact that it was loading this corrupted info from the cache and DB files and not recognizing that the actual fonts in the system.
Font Finagler
http://homepage.mac.com/mdouma46/fontfinagler/
Suitcase Fusion
http://www.extensis.com/en/products/font_management/product_information.jsp?id=1060
Font Doctor
http://www.fontdoctor.com/