Database corruption was the cause of the problems over the past few days. Fixed that last night.
The cause of the database corruption appears to have been due to technicians at the server datacenter. From what I can tell, during a scheduled network upgrade which required taking many servers offline for only a few minutes while adding upgraded network hardware, the techs seem to have not shut the server down properly. They probably removed the power cord to the server before it had completed the shutdown process. This is very bad for a database server (or even any server) and is very likely the cause for the database corruption.
The forum software had nothing to do with the problems. GC is currently running the most recent version of vB2 which was released in mid January. Moving up to vB3 is like going from Windows XP to Windows 2003 (or their next operating system). GC's version of vB is like having Windows XP with all the Windows Updates downloaded & installed. Anyhow, not really trying to debate vB2 vs vB3... vB3 is a very nice upgrade with new and improved features. I've been planning on upgrading to vB3 during the spring of this year - so probably within the next 2 months or so. I'll post more about that in
John's next vBulletin upgrade? in a few minutes.