I play mine from four to six hours every day, and I haven't had a single freeze or lockup.
I made a studio-class recording with it today, for a friend who will put a harmonica track on it.
I'm looking forward to OS4, but I haven't had any problems with OS3.
You seem to be snake-bit when it comes to the Audya. Hope it works out for you eventually.
The sound card went out on the one I had earlier, but no problems with this one.
AJ said we might see OS4 by next Friday, but he is at the mercy of the guys in Italy.
DonM