My comment earlier was to prompt questions regarding alternatives to table layouts.
A table layout locks you into inflexibility to change the layout, and doesn't make a great deal of sense to non-visual browsers (screen readers, search engine spiders etc), especially when an image map is used for navigation. "CSS layers"? - there is no such thing as layers. This is Dreamweaver-speak for absolutely-positioned divs which are just as bad as tables when generated by Dreamweaver (Dreamweaver should not be used to create layout in design view).
By thinking content first, then styling that content to achieve your look, much more possibilities are available, but it does require a completely different approach which can be difficult to grasp initially.