Same problem here. Trying a clean install of ProDADA 4.2 on OS X 10.6.4 server. The default MySQL is in use.
MySQL is fine, connections to 127.0.0.1 from dada user work.
Can you start a different thread, actually - it's not the same problem, the OP thinks it's because of a socket problem - you haven't really mentioned anything like that, although it could, potentially be that.
I develop on Mac OS X, so it's not an OS configuration problem, but do post a new thread and perhaps do the same debugging stuff I mentioned in this thread.