I decided to upgrade the RAM on my MacBook from 2GB to 4 and duly bought some online. I was careful to make sure the spec was correct and when the units arrived they were the same shape/size as my current RAM and stickered accordingly. Having successfully installed them I went to check on the system profiler, which tells me that they are 1333Mhz instead of the 1066 that they should be. I have contacted the vendor and am awaiting a reply. But as all appears to be working well, should I have cause for concern?