Just noticed something odd. In Firefox, when I load my blog at http://workproduct.wordpress.com, my Gravatar image (in the Gravatar widget at top right) is off-center and surrounded by a gray box. In Safari and Chrome, it looks fine (no box; centered, I guess, though maybe you just can't tell because there's no box around it).
The image looks fine in Gravatar itself - I don't think there's a white border or other reason it would be off.
Any idea what's going on? Anyone else seeing this?