Unfortunately, your motherboard only has a 4+1 Power Phase, meaning it's barely enough just to keep the 8350 at it's stock 4GHz--anymore and it can't supply enough power to you CPU er go the crashes.
Sorry :/
i had an ASRock Extreme3 990FX with the same problem--I could push my 8320 to 4GHz but not a hair past. Then I switched to an original Asus Sabertooth 990FX with an 8+2 Power Phase and I'm happily humming along at 4.816GHz.