DW 2004 help

Yes, I know that I should post it in the DW forum but no one noticed my thread there, so

I dont get it, I create a page it all looks nice and cool, I create many series based on that template but behold! It looks completle out of shap! When I work on it in DW 2004, it looks all nice, but when I preview it , or upload it, it is streched out of proportion! Help!

The page should be 750px wide.