I'm experiencing problems with transparent png images saved with gimp recently, but only on this site. If I upload the image to my blog it looks fine, but when I add it as my avatar here, the background becomes black. If I upload an old png file is looks fine too, so I guess it must be some Gimp exporting settings that is not optimal. I have no idea which one is it. I have even deleted the gimp settings folder, but it didn't help.