I was just bit by some assumptions I made with ADOdb, MySQL 5, and transaction support. I’ve been using Smart Transactions with success on other systems, but during my current project I noticed the SQL commands were being processed without respecting my FailTrans() call.
Turns out I was using a storage engine that did not support transactions. While InnoDB is ACID-compliant, MyISAM has no support for transactions. Whoops. A few ALTER TABLEs later and I’m back in business.