Well, it took a lot of investigative work and effort, but my host service — Bluehost.com — finally found the source of the problem. Their customer service is the # 1 reason I’m with them. Yet again they went the extra mile, spending several hours on the problem offline.
I’m also thankful to all those who offered assistance via email and Twitter. It’s nice to know people are out there who have an appetite for paleobabble!