Sometimes heading doesn't render in IE7

Question

This is strange... I have some files where one of my headings seems to randomly render or not render. This makes debugging difficult...

Check out this page first. You should see the word "Synopsis" in green above the main text. Sometimes it's missing, but only in IE7 (I have not tested this in IE8).

If you then browse around using the nav on the left, sometimes the header shows up, and sometimes not. Same for the other pages in this section (book 1, book 3, etc.).

Any ideas? Does this work properly for others using IE7? If so, then maybe it's a problem with my own installation of IE7 or Flash...

Thanks,

David