So... I had an original 2.53 uMBP that I ordered Oct 14th, Right when they came out. After a few months my airport card stopped working (), took my computer to apple store. After replacing the Display and Logic Board, the card still didn't work. They did a "CRU?" and issued me a new machine )). They didn't have the original 2.53 in stock, so they gave me the 2.66 (15" without the new internal battery, speed bumped Jan '09 at Macworld). Apple did the data migration. Everything appeared to be fine, but the only problem I am having is that the System Prefrences (I am running 10.5.7) are hanging alot, takes almost 3 mins to switch between screens, randomly freezes, and sometimes when it is really locked up I need to force quit System Prefrences (Force quit menu says "Not Responding" next to the System Preferences. Anyone having similar problems? Any suggestions besides nuking it and doing a clean install? Sorry if this should thread should go under a software category and not a hardware category, and thanks in advance for any help/advice.