Original post by: jbeltzner ,
I just tried 2x4GB Corsair 1333 modules in a late 2008 unibody MacBook. The system booted and recognized 8GB of 1333 RAM, and everything worked until I tried to install OSX Lion. During the install process, I got kernel panics left, right and center. I had to remove the 1333 RAM and replace it with the old RAM. I don't know if there is something specific to operating system upgrades that would have caused the problem.