The messages "Loading Web-Font ..." are in the corner and the page takes a long time to render. It eventually comes up.
Is this a same-origin-policy font problem?
Davide P. Cervone
No, this is not the same-origin policy issue; that is only for Firefox. There was a important iPhone bug fix in SVN 604, so if you are using a version older than that, you should update to the latest SVN. This change hasn't been included in a packaged version of MathJax yet, so you will need to use the trunk SVN version to get the fix.
PS, I'm not sure what version is currently on the www.mathjax.org web site; it may need updating, too.