Every picture I view from the Railway Herald site's Imaging Centre causes "Error converting PNG" to flash briefly on the bottom line, but only when the image is viewed for the first time - refreshing the image, or going back to one recently visited, doesn't show the message. The main image is always displayed successfully, though.
Example URL: http://www.railwayherald.com/imaging.centre/showimage.php?image=214023&gallery=X3 Any explanation? Dave