Be more specific. A broadcast is local to a subnet. The DMZ would be another subnet, and therefore wouldn't be part of the broadcast.
The reason I say be more specific is the only exception I can think of would be for a directed broadcast. The default for new router IOS is 'no ip directed-broadcast' and I would assume the PIX would be the same. You wouldn't want it otherwise as far as I can think of, otherwise you're going to be a possible smurf amplifier. [sig][/sig]