If the domain name was a three-word-key phrase with hyphens, or underscores, it may well inadvertently fall foul of, say, G's recent changes in handling suchlike. etc.
Speculation, of course, but another factor to consider before using full urls in markup.
Code bloat: Actually, it was that 'orrible Alexa that prompted me. A few years ago they used to display your site's load-speed, and I was shamed by being in the lowest third.
I've been in the fastest third ever since.
Switching to all css really helped. No tables at all.