Hmm, yeah. I suppose it must be a bug in Safari. It keeps the image at the width it's been set at (notice if you go over an even wider image it'll stay like that...)
Might not be perfect, since not all the images are the same height, but you could use percentages for the width and height. Or, you could extend the function handling the mouseover to put in specified heights and widths for you.
By the way, there is a whole
forum dedicated to this kind of stuff, right here on macnn
