Cable management 101 : Is a cable close to hitting a fan ? -> is it blocking airflow ? -> Done
What ? you are running your card at 900-950 mhz at stock 1.088v ?
On mine moving above 833mhz I am taking risks, Some goes to 875, none 900 even less 950
What PSU do you have, that's an important part.
Thermaltake Toughpower Grand 1200W (TPG1200M EU)
It's working 24/7 from July, and I had only one problem:
https://bitcointalk.org/index.php?topic=53620.msg640540#msg640540What voltages did you test?