i would recommend using the "AMD Directions" on setting the heat sink. it calls for twisting the heat sink and blah blah blah... just watch the video.
ok that video is not the one i remember. It goes against almost everything i know about installing the heat sink. make sure after the heat sink and processor make fist contact, apply pressure while making a back and forth twisting motion which will help rid of air bubbles. other then that, experiment with different sizes of beads. "Install and Remove" see what kind of pattern the AS5 makes. it doesn't need to cover the entire processor. I could be wrong but when i install my heat sink, i like to cover as much of the processor as i can without having any leak out the sides. right now that seems to be about 1/3 to 1/2 grain of rice