OS X snow leopard

error message: (node)Hit maxfile limit. Increase 'ulimit -n'

ulimit does not function as required for os x 10.6

launchctl and launchd control jobs, vanilla flavoured instructions required... notwithstanding the man page neither of the following wfm

$ sudo launchctl limit maxproc 512 1024

editing .launchd.conf and rebooting