Reading those... I don't know, right now I feel safest going with Apples memory without going overboard (reason why I'm getting 2 GB for now). Until the prices settle down and these quality issues get settled, that seems like the safest path.
I just bought some RAM for my MacBook Pro today and the person ahead of me was looking for RAM for a Mac Pro. This was at a third-party RAM store that's also an Apple-certified dealer. The man helping the guy in front of me recommended ALL RAM going into a Mac Pro come from Apple, prices nonwithstanding, because of the heat-sinks and the fact that it's such an important, expensive machine and you don't want anything to go wrong with it.