It sounds like you are using the OS X 10.6 Snow Leopard operating system on your computer which Line 6 does not currently support, but we do have beta versions of software drivers for.
First, download and install the POD FArm 1.11 software onto your computer. Then, before connecting your UX2 hardware, download and install the 4.2.5 drivers for the Snow Leopard operating system from the following link:
http://line6.com/community/docs/DOC-1628
Regards,
Line6Hugo