Anchor link causes some content to disappear

Sorry, clearly this isn’t a modx issue, so we can discontinue the thread. FYI, it turns out this problem is already well documented:

http://www.positioniseverything.net/articles/onetruelayout/appendix/equalheightproblems

Thanks again for looking.

Glad you found it. For others with similar problems, a good first step is to search your .CSS file for the word "hidden."