I have noticed while working with several divs, the divs in dreamweaver will suddenly overlap each other and look really messy. This happens even though your code is correct. My site now looks perfect live on my website, but in dreamweaver with the exact same code looks messy like hell. Just like it doesnt read the .css file but it does. Anyone experienced something similar ?
Edit: Cant be dreamweaver since the site gets messy in Opera and Firefox as well, i guess its only IE showing it correctly :)
Don't code and test your site in IE - write your code for Firefox (or Opera) and debug for IE. Not sure which version of Dreamweaver you have, but it tends to NOT render code in the preview pane as well as it should. I suggest using the code writing WYSIWYG and viewing/testing how it renders in Firefox.
Dreamweaver will only render absolutely positioned divs correctly. It doesn't do a good job of rendering floating divs - so in View/Style Rendering, I have turned off "Display Styles". That way you see the page without styles in Design View, and in the preview you can see the styles applied.