Yep, the background color. It's a little dull, but that's just my personal preference. So I don't know what other feedback you've gotten, but take what I say with a grain of salt.

EDIT:

Also on pages like this one: http://disqus.com/people/danielha the text of the comment and the box on the right (points, replies) overlap sometimes. Minor quirk, but work getting fixed.

And you might want to make the green arrow (on hover) a bit more noticeable... kinda like the red arrow for voting down.

Sorry for all the cosmetic feedback, but I haven't gotten around to creating an account to give technical feedback/bugs.