[LAU] JACK on Pi... almost working

I was playing around with trying to use a Pi as a synth. So far so good except for two problems: 1) I've run into this: http://comments.gmane.org/gmane.comp.audio.jackit/26263 But I'm already using jackd2_1.9.8~dfsg.4+20120529git007cdc37-5+fixed1~raspbian1_armhf.deb which supposedly has Dbus removed/excised/banished/purged/kicked-to-the-curb. And yet, no dice, same error. Haven't had time to investigate it yet. I went back to jackd1 (wow, it's like it's 2007 all over again). 2) The sound coming out of either the built-in audio or an external C-Media USB interface is cracking and nasty, with obvious aliasing distortion. Any ideas why? I've tried 44.1k and 48k. No xruns tho, which is nice, at 44100/512/3 using jackd1 and fluidsynth. I've got it overclocked to 1Ghz, all is well with that (ran the self-test), and using the performance guv'na. I haven't tried with my FastTrack Pro yet because the Pi can't power it at the same time as a MIDI keyboard, and a working power cube for the keyboard has gone missing. The crackling/aliased sound is the big stumbling block though. Any ideas? -ken