A 2' x 2' area is suggested as the ideal amount of space to polish at a time.
I find that if you think you are moving the PC to slow chances are your not

I make it crawl over the surface to get the results I want. I usually end up doing a 1' x 1' area because I move it so slow I dont want the polish to dry up. Which may be happening to you because you are doing too big of an area (1/3 of a hood at a time is a lot of distance to cover at 1 time). I usually just put the polish on the pad and smear it with the machine off then turn it on. I use very little polish on the pads with the PC so it takes like 2 quick swipes to get it spread out.