So i bought my Macbook with 2 gigs of ram and upgraded it with 4 gigs of OWC ram (back when it was $145, now its $69) and the freezing began! Ive had two replacements from OWC, but the new ram doesn't seem to make a difference. Even with the original 2 gigs, the macbook doesn't fail to freeze. Something tells me this issue goes deeper than 2 or 4 gigs of ram. Perhaps there is an under volt or power issue somewhere. Though my phone support has long since expired, the apple rep. thought my problem was so ridiculous that he still accepted my call (usually they just say sorry, cant help ya) Unfortunately ive gotta send the macbook in for repair, but hopefully they can nail this problem out. So instead of troubling yourself with finding the best ram and spending time and money getting replacements, have apple use their time and resources to fix their flaw.