User-Agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8a3) Gecko/20040720 Firefox/0.9.1+ Build Identifier: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8a3) Gecko/20040720 Firefox/0.9.1+ On Mac OS X, the square root sign has a think black bar for the top part of the square root. On a Windows machine, this does not happen. Reproducible: Always Steps to Reproduce: 1. See example in URL.

Please make sure you have non-buggy fonts installed (see the MathML fonts FAQ on the Mozilla website).

rendering error here matches the torture test example in bug 228804 see also http://www.mozilla.org/projects/mathml/fonts/ *** This bug has been marked as a duplicate of 228804 ***