The reason why your cpu and gpu were overheating could have been the thermal grease, it happened to me also.
Another reason could be that both cpu and gpu heatsinks gathered a lof of dust, and reduced the airflow.
Your temps now are excellent! I agree about the stock coolers on the gpus. They suck and keep temps near at the cards limits. I have 2 geforce 8800gt's and i have changed both their coolling.
Always clean the previous thermal paste when changing your coolers.
The best thermal pastes to use, are arctic silver 5 and arctic cooling MX2 or MX3 i think is out now.







