I know this is a real amateurs question, but here goes:
I use Dreamweaver MX and use a lot of layers as I find them easier to use and more flexible than tables. The problem is : my site looks fine in design view (I'm afraid I do almost everything in design view, I've not got into hand coding, I know I should) and in Internet Explorer its fine - it looks just the same. The problem is that when viewed in Firefox, the font is always a bit smaller and so the text is often not in the right postion in relation to images.