You got a couple things wrong. The machines are the same, from the september and november batch. They were just overclocked. I got one in sept and my friend got it a couple of days ago. It's hashing at 19.3 GH/s but at higher temps. In the miner status, what does the frequency tab say?

Also, the thing about error while reading temps...I'm guessing it's just a bug. I always get it if pool 0 dies and it has to switch, but it does not affect performance in any way. The hashboard stopping thing, I only got it 2-3 times.