To the OP, there was a known issue with certain batches of the 3 (mainly silver). Mine was swapped out, outside of the 12month period for the same issue. I have owned several different versions and have only had that one issue. GP were great, dealt with guys in Holland.
The SD card used can also impact upon the GoPro experience. I have put down my thoughts here - http://www.unsponsored.co.uk/press/?p=1836