Hardwood spliting at tongue??

[Omega Supreme]

I am installing a 7/16" Santos Mahogany hardwood floor using a HighPro stapler @ 70 psi and 1/4" x 1-1/2" galvanized staples. Every so often the tongue will split where the staple goes in. Is this ok and normal? It usually happens where the staples kinks up due to the harness of the wood. A friend of mine told me that galvanized nails/staples are softer than non galvanized nails/staples and that I might want to try non galvanized staples? Is this true and is it ok to use non galvanized staples? Thanks for any advise that you can give.

[Carpets Done Wright]

You only need 1" staples for 7/16" thick flooring. 1" work up to ½" thick flooring. 1¼" long, for up to 5/8" and 1½ long, for ¾"

[Omega Supreme]

The directions on the box say to use a 1-1/8" min. Would 1-1/4" work better? I wanted to use something a little bit longer than the min. Is it normal for the tongue to split from time to time? If not should I replace it if it splits? Its not splitting near as much now that I have the psi set @ 70. I had it 80 psi thinking that it would help push the staple in w/o kinking it. But after doing about a 1/4 of a room I noticed that if I put a lot a pressure on the back of the nail gun that it worked better and didn't kick back. My dad told me that if it split a little that it would be ok but i noticed walking on some spots that the floor would crackle and pop. So i then bumped the pressure down to 70 psi and it cracked a lot less but i have more staples that kink up. Anyway let me know what you think. I'm really worried that I may have messed up on that first 1/4 that the tongues were cracking more. Is that going to cause me problems in the future or will it be ok? Thanks again for any replys.

[Carpets Done Wright]

Your staples need to be about 4-6" apart, down the boards

[Omega Supreme]

Thanks for the reply CDW. I have been using 4" spacing. Does the occasional split hurt anything?