I am planning to buy rams for my white macbook (latest one) I did some research, and I found out that 8GB is the maximum capacity for the white macbook. My concern is that.. should I buy 1333mhz or 1066mhz ..? I know macbook will automatically read as 1066 mhz. Is there any stability issue using 1333 over 1066 for my macbook ? Thank you !