I've tried both Generic, avi audiocopy profiles (h264/xvid) and both have the same problem. My new machine is a new build XP Pro (32bit). Essentially I've just got a beefier set-up of my old pc, but without the baggage of loads of old encoders/progs etc. I hoped my slimmed down build would fly.
I always use a twin pass, and usually run unattended. I'm running tests from DVDS with small files, rather than banging my head against a wall with the known 'problem' title at the moment. The problem only occurs on audiocopy, and it doesn't matter whether the track is stereo, or 6 ch.
I did notice on one attempt that during the second pass, the fps dropped below 1 and I aborted it.
Currently I'm testing on 188.8.131.52 again, but tried earlier builds in vain.
I'll update when I have a clearer picture of what is happening and when.