Nope. It will not make any difference at all.
What does help is reducing the amount of code relative to the amount of content and moving the content as close as you can to the top of the script. Most XHTML sites use divs instead of tables, which reduces the amount of code, but you can do the same thing with an HTML 4.0 site and get the same results with search engines.
Regardless of which coding standard you use, it sometimes helps to eliminate all of the errors because it makes the code easier for spiders to parse and makes the site render faster and more reliably across different browsers.