Frank,
This doesn't surprise me at all. I had many MacBook Pro replacements (4) before I got a PERFECT system. They couldn't beleive how many times I had problems. The people at the stores are great though because they just kept giving me a brand new one and taking my old one back. My machine didn't have to see a genius and I didn't have to pay a restocking fee for each replacement. These people have been very kind to me. Matter of fact, I'm going to call them up today and thank them for all their help with my MacBook Pro situation. Good luck with your second MacBook, I hope you don't have to keep getting a different one!