Problems with APex440 USB Mic

I am trying to use a APEX440 USB mic but when I select it from the drop down menu in Device Manager and try to switch, I get an error saying cannot initialize. The computer I am using in a new iMac with OS x 10.9 and I am using Cubase studio 4. Any help is welcomed!

Best,
Robbie

http://www.steinberg.net/forums/viewtopic.php?f=25&t=8824