I haven't heard of anyone being penalized for using <div>s... It is very widely used for CSS layouts, which is supposed to be the up-and-coming standard for all layout (use XHTML for structure, and CSS for appearance...).
I realize this is may not the right forum for this thread, but... my partner has done well with one of our sites for a four word phrase on most all of the engines. However, I have been paying particularly close attention to his results on Google where there has been a real dog fight for the number two spot (#1 is owned by a Yahoo company so I don't believe it's going anywhere too soon). His results since this last crawl have increased our site to the number two position and the only change he made was to four or five the <div tags we had in some graphic images. It looks like changing that tag to <center><img..... has made the difference.