Glad you somewhat have it figured out. I couldn't find anything wrong when using my UX2, but I guess I assumed you also didn't have anything else going on in Sonar either. 1 thing at a time is really the only way to trouble shoot something like this, considering the vast amount of third party plugins and instruments, let alone system configurations throwing something awry.
I still have no difference when recording through PF dry output and without PF dry, when everything in PF is disabled and I mean everything, gate and all. I listened through my Event 20/20 monitors and through a low priced pair of Sennheiser HD phones, so that's still kinda weird, but I guess every set up is different and I'm using the UX2's phantom power, which could be the difference. Cool you got somewhere with your problem, good luck with the rest.