Hello,
I have a big problem with my line 6 UX2 (on Mac OSX Mavericks); I have got a (very) loud and permanent noise (even if I'm not playing), I checked if I've installed the last version of the driver with line 6 Monkey and yes, my version (7.3.6) is the last one.
Here's what I get with adobe audition (same sound problem with pod farm and guitar rig):
I checked if UX2 was selected in the options, if UX2 was selected for "line in" and "line out", and also for the clock. But the only one category I can choose is "core audio", I don't see UX2 or stuff like that.
Sorry for my English, but I'm french, so I apologize if you had some troubles while reading/understanding me...