I think this may not have anything to do with the area tags, but it could be I guess.
here is a link to download my source code since it is very hard to explain http://temp-share.com/show/YgFHjkPEy
Do you have any idea how to get the same functionality in FF as chrome/safari?
On your image tags you need to place a hash tag before the map name.
<img class="pic1 day" src="img/LMday.png" usemap="#img_map" border="0" width="2798" height="450" alt="" />