In XHTML1.0, <img/> is somewhat different in Mozilla from in IE. For example: In a table:
<table><tr><td><img src="../sample.gif" alt="sample" width="16" height="16"/><td></tr></table>
then in Mozilla, the image is somewhat heigher than in IE. That is, there is some margin under the image, which is for no reason. Only after I wrapping the <img/> into a <div/> element and using CSS to mark the <div/> as css="height:16px;overflow:hidden;" did the image displayed into its size. Maybe this is another bug of Mozilla 1.7.3.