Arduino Uno usb drivers not showing mac os 10.8.4


I can't get the drivers to show in the serial port list for my Arduino Uno.

I've installed the drivers with no errors, even restarted my mac, but no joy.

It worked fine on my old one (which used a previous OS - not exactly sure which it was) but not this one (10.8.4), has anyone had this problem / have a magic way of solving it please? I'm desperate to get going again!

Thank you.