When the bounty line appears, on my system the line is not high enough to fully display the arrow:
Erroneous rendering http://img7.imageshack.us/img7/9374/bountyarrow.png
(and of course I'm using the default text size).
I'm using Firefox 3.6.8 on Linux, but it looks the same in current versions of Chrome and Opera here.
EDIT: The original question that has a bounty. Note that the bounty ends tomorrow.
Another question has a bounty that lasts 7 days at the moment.