Steps to reproduce:
1. Visit http://trac.macosforge.org/projects/ruby/wiki/WhatsNewInLeopard.
2. Look at scroll bar, note tiny thumb.
3. Scroll down. Keep scrolling. Nothingness.
Firefox doesn't see this. This is a recent regression as this does not reproduce in Safari that ships with 10.5.
I saw the bug the first time I loaded the page, but when I reloaded it it had the correct height. I am pretty sure I have seen this behavior on trac.macosforge.org pages with older versions of WebKit (going back at least as far as the one that ships with 10.5). Those pages use <http://trac.macosforge.org/js/bgsize.js> which gives an error on WebKit.
The line that throws the exception is:
TypeError: Undefined value
The trac.macosforge.org site has changed. There is no Internet Archive saved for this URL. Moving to RESOLVED/FIXED.