The SO question page markup is flawed in Opera browser. As you can see on the screenshot, comments are overflowed with the
Careers block. This is with
Opera/9.80 (Windows NT 6.1; WOW64) Presto/2.12.388 Version/12.11
upd The bug shows up occasionally, not in every question, but still quite often. Actually it is not always reproduced in the same question. Probably depends on the contents.