To your knowledge, is there a difference between the new uMBPs that came out in late 09 and the ones that are produced now? What I mean is should there have been any problems in earlier production that existed and have since then been corrected? I just bought a MBP 13" 2,53 (I waited since Christmas for the update, but just couldn't wait anymore...) and doing a battery test, I noticed it said my computer was 8 months old. Also, I have the Chi Mei screen 9CA0, which I imagine is the first one used (simply by the "code" though.. not a clear "fact"). How can I find out again when my computer was built? Do this really make a difference (any difference between an earlier built and a newer one)? Is it normal to have bought my computer last week and for it to be 8 months old?! I'm a little puzzled, and a little worried..