If I look at the page with 2000021308 on an 800x600 screen, I see a horizontal scollbar which isn't supposed to be there. If you look at the References section of the document, you will see that the URL in  is responsible. The weird thing is that the URL in  is wrapped properly. I can't see what causes the difference. Resizing the document or viewing at 640x480 doesn't make a difference.
Looks like a problem in the line wrapping code. That URL should be displayed on the next line, but instead we allow it to overflow on the current line
mine! mine mine mine! all mine! whoo-hoo!
The dup should proboly go the other way, but there are a lot more comments and testcases on bug 34291 *** This bug has been marked as a duplicate of 34291 ***