Problem with layer on Mac & Netscape

Hi,
I do not understand why my layers don't keep their absolute position on Netscape. I put the little script that dreamweaver gives to correct it, it works on pc (ie + netscape) but not on Mac with Netscape. I really don't understand & little bit nervous

U can see it at: www.labelmark.com/fr/home3.htm

Thanks for your help
Thieg