Expanding or collapsing the last section of the FAQ ("How do I search?") sends you back up to the top of the page, while the other sections expand nicely without jumping around the page.
The problem is that there are two HTML tags that use the same CSS ID ("search"). This should be fixed the next time they deploy.
The revision for which I reported the bug is 2011.8.24.3; until the revision is that, the issue should still be present.