This might help if your running Lion.
Mac OS X Lion Compatibility
Pulse Oct-14 • Announcements
Pioneer has been researching compatibility between Pioneer hardware / software and Mac OS X (10.7) since its release. As soon as we've verified compatibility with our products, we will release compatibility information on the support site and there will be announcements made here in the forums as well as on social media sites (Twitter, Facebook, etc.)
Current software (Firmware and Driver software) may not work with Mac OS X (10.7) properly at this moment; visit the support site for a full listing of hardware / software compatibility and status.
Thank you for your patience!