new header

So I spent some time in Paint.net today and put together the little header image you see above. I'm not sure if I like it - if it's in its final iteration, that is, but what's bugging me is that I can't for the life of me figure out why that little gray box is up there on the right hand side of the header. That is NOT in my .png file. If anyone has a clue, please let me know.