Assuming that you are using MacOSX, try to find out what is your limit by doing:
launchctl limit maxfiles
I have a clean install of OSX Maverick and I have:
maxfiles 256 unlimited
If your system does not show that, try to edit/create a /etc/launchd.conf
with something like:
limit maxfiles 256 unlimited
** Increase 256 to a higher number if that does not helps. Remember to reboot.
Check out this answer: https://unix.stackexchange.com/questions/108174/how-to-persist-ulimit-settings-in-osx-mavericks