i heard not all 8 gig sets ups work, correct?
why would that be?
Your Apple MacBook New Unibody Plastic 13-inch (DDR3) 8GB Memory only supports memory modules made with a specific type of chip. Should you find what seems to be the exact same memory modules elsewhere for a lower price, it is very possible that the cheaper memory modules will not work in your system. By using Memory-Up's Memory Finder, your selected memory modules are Guaranteed To Work or your money back.
This is what I am concerned about. This true or just trying to sell their product?
from
http://www.memory-up.com/Memory/AppleMacBook9770.html#