Just tried mine yesterday. Froze up 3 times even after the update. Tried to upload a video to youtube and failed to upload. Something about an incorrect file or some junk. I did my research and only got the black for the high fps knowing it has glitches. Guess I'll have to work through them.
What brand of micro SD card are you using?
I ask because I have the gopro 3 white and when using my official "SD" brand micro SD 2 gig card that I already had, I havent had any problems yet... BUT, I bought a "HC" brand micro SD 32 gig off ebay and my first video is good no matter how long I let it run, but after that all the next video's are corrupt, and thats not even shutting off the camera power. That's just pausing in between videos.
Are your corrupt videos coming up as "UNDF"(meaning undefined) when you try to play them from the camera, or u/l them to computer and play them?
Ive also been doing some reading and have seen that peeps are having some problems with the "PNY" after market brand of micro SD card.
I know there are ways of getting that undf video back yet, just havent gone their yet.
Let us know how it goes!