About six months ago I had the logic board replaced in my late 2008 15" MBP, after it stopped recognising external displays. Now it won't recognise any USB sticks (tried 3 that work on other computers), though it does send them power (lights flash) and will let my iPhone sync. Have tried restarting, PRAM and SMC resets, nothing works. This happened a month ago and it started working again after a firmware update. What could be going on? If I take it to the geniuses they'll want tp keep it for a few days to fix and I have no time! If it is the logic board again, would that + replacement once before mean one more thing going wrong = new MBP? Because the screen flickers, too... ugh. Don't need this! Am finishing grad school and leaving for Haiti in about 3 weeks, can't get Mac support there!