TFL got more memory Saturday, and rebuilding the indexes got fowled up Sunday night. I didn't notice until mid-morning, but I suspect the broken search index was making the new-post process unreliable. After a post gets committed, it gets indexed for searching. That second part was failing, and vbulletin isn't the most robust web application on the planet. So a problem that should have only affected searching (which is irrelevant because the search index is being rebuilt at the moment, and it'll get to those new posts in a day or so) ended up causing inconsistency across the board.
"Think about it a little more and you'll agree with me, because you're smart and I'm right." --Charlie Munger
Dreams and schemes and circus crowds...