Well, not much to say, look at the subject. http://i475.photobucket.com/albums/rr111/Ryqiem/Billede2.png Screenshot in safari, from the portfolio page.
ThemeForest needs some minor tweaks in Firefox as well but I do believe Envato has been working on a refreshed design for the marketplaces which might be why these minor issues haven’t been fixed yet.
They also might not have been fixed yet if nobody brings them to the attention of the support staff. You might want to send that to them so they are aware of it.
I know that there are some minor issues. But, as Jarel said, I’m pretty sure that they’re working on a new design for the marketplaces.