Until IE becomes more standards compliant and all browsers began adhering strictly to the w3c coding standards, it will be nearly impossible to create one set of coding that renders beautifully across the various browsers. Many people do use one style sheet, but then include code specifically to work around junky IE. Anyhow, until that time, tables are still not such a bad idea for positioning of content and data.
This website generates css code for tables, which is kind of a nifty idea.
For more information about cross browser compatibility: