I've observed this a couple of times now. I truncated a table, and now anytime I do any SQL operation on that table, MYSQL client will stop responding. I can open a new client and query any other table. If I truncate another table while this is going on, it will also become unresponsive. It seems to take a very long time to "fix" itself.
Eventually, it does, and I can truncate the tables and run any other query operation against them.
Does anyone know why this would happen?