I get load failures due to deadlocks somewhat frequently on a particular SQLServer 2003 DB. In this case, it is the database throws an error when it resolves the deadlock by killing the QV request.
I work with another DB -- Lotus Domino -- where the DB server sometimes goes non-responsive and the load just hangs. In this case I rely on the Reload task Timeout Seconds to end the reload task with an error.
In both cases I use the reload alert facilty to send an email on failure. In the case of the non-responsive DB, the email says the cause of the error is Reload Task timeout, but everyone knows it's caused by the DB.