This is what I'm getting after connecting my UX1 to a Macbook Pro (mid 2011). It's being recognized, plays the sound (as a soundcard and from Pod Farm) but it's very low volume, distorted and cracking/popping. It's impossible to play the guitar, and barely possible to hear the audio from MP3. Has anyone had similar problem?
Make sure you have the Newest Monkey, drivers and firmware.
Run the Monkey to get the updates.
If you already have done this and have all green ticks when you run the Monkey you may want to contact Line6 directly via a support ticket.