The forum was offline for almost a day. My host (MacHighway in Denver) was on the case and discovered a session table related issue for the forum's database. Why it occurred is a mystery. In the seven years since I created this forum with the help of a vBulletin developer we've only had one or two issues and each time the MacHighway tech support was superb. Yep, that's an enthusiastic endorsement for the service they provide.