I think the problem I was having was using 3 inch nails instead of 2 1/2 because the Hardware store didn't have them. The nails were bending. I tired a 2 inch nail and a nail punch and it worked. I am assuming that the trick is to stick with the 2 1/2 inch spiral nails and to use a nail punch to drive it through the carpet and underlay.
Answer:
Don't use the nail punch or you'll cut the carpet mesh. Just one extra hit with the hammer will drive the head down through both carpet and underpad and do no damage whatsoever.
