A week ago we were watching TV when our 622 turned itself off, then when I turned it back on the fan came on full blast and then turned off. For the 18 months we've had it, the fan would be on all the time - quite annoying but seemed normal for the 622. So after it comes up there seemed to be no fan at all, and we noticed more artifacts than usual (could be coincidence). We called it in and the guy stepped us through a few things and then decided we needed a warranty replacement. That arrived and I installed it - and it behaves the same way. Now I'm wondering if we A) Have a second bad receiver, B) Had a receiver that was bad but corrected itself, C) Are imagining things, or D) Got new firmware (448) that makes the fan behave differently. Any comments from other 622 owners? What's normal? Thanks!