arctic cooler accelero 2

[hey-hey-ocuk]

i replaced my stock x1900xt heat sink and fan with the accelero 2 today and after a about 4 hours of just reading stuff on the net i decided to give atitool a try and i couldnt get above 605mhz my voltage regulator was at 80c and my card was at 70. and it really *****d up everytime i tried to get to 610.(which it is supposed to do). anyway i thought i had not seated it correctly and took it off again and now both the graphics card and my system temps both idle at 50c. did i not put enough thermal compound on it this time? do i need to retry with more. finally how do i lower the system tempn as the vga heatsink seems to be blowing hot air over the southbridge.

spec

conroe 6600
p5w dh deluxe
saphire x1900xt
beantech igloo 7 case(for what its worth-a cooling nightmare).