CSS seems like the perfect solution to your Web design problems. While it's good, CSS isn't perfect. And that's because not all Web browsers support CSS in the same way. Some CSS-capable browsers only support a subset of the CSS specification, while other support most of it.
I've tested CSS table layouts in several Web browsers. I've found that the following browsers do the best job of rendering CSS in general, and CSS table layouts in particular:
Opera (Windows and Linux)
Mozilla (Windows and Linux)
FireFox (Windows and Linux)
Konqueror (Linux)
Safari (MacOS)
Internet Explorer for Windows also does a pretty good job, but I've never been overly impressed with Netscape's CSS support. But you still may run into trouble. Older versions of certain browsers -- especially Safari and Opera -- don't support CSS all that well. CSS-based layouts may not work properly or at all. For example, columns may run into each other or appear stacked on top of each other.