Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
Wow....I just had the same problem with my hero2. It would turn on, start recording and a few seconds later shut down again. Sucks when you loose great footage because of an obvious manufacturing problem. I was going to buy a hero 3 but not sure I want to go that route as I've heard issues with flooding....and GP won't warranty anything ...Geesh
My camera still does not charge fully (the suspect reason for the random shut offs) after the firmware update. Yes I do have one of those Sandisk cards... But what that has to do with charging the camera?
I looked through the Hero 2 section of the GoPro forum for similar complaints and came up empty.
Most of the Hero 2 issues seem to be bricking with the latest firmware update. The only thread about turning off while filming seemed to be a battery connection issue---it was a bicycle mounted camera and folks speculated the bumping was breaking the connection.
The FAQ section strongly suggests charging via a dedicated USB charger---not connecting to your PC---but that's mostly to keep unwanted files from being loaded into the camera memory.
I suggest the following, not necessarily in this order: contact GoPro, and try a new battery.