I know plenty of DBAs from my old work places, working on very large DB's but they are all experts in the wrong software - Oracle, DB2, Teradata, Netezza etc. Its finding someone that knows mySQL well that is hard Even on the phpBB forums they wont answer questions on how to tune mySQL for phpBB itself, its like getting blood from a stone
As Chris has said, chat may or may not be back permenantly. It uses the DB for some stuff and may be causing the server to become overloaded. We need to work out if its a badly coded mod which will always kill the DB or if it ok as a mod put a bit too much load on the DB highlighting the problems. Small but significant difference.