So my mac is running leopard at first (10.5.6 if i remember) Then i upgraded to snow. I saw my friend's newer (latest pre-thunderbolt) MBP backlight if increased/decreased there's a smooth feeling to it. running an older version of SL (10.6.6 mine is 10.6.7) Mine is not smooth at all, it's only smooth if the ambient light sensor detects a change. Is there a damage or defect? Anyway to fix? MB446ZP/A. 2.0GhZ, 2Gb 1067, 160Gb 5400. 10.6.7. Build version 5.1, MB.