Issues Overclocking GIGABYTE 560 TI

So, I've tried overclock my GPU using GIGABYTE OCGuru. My base mhz. is at 822. I overclocked by increasing the voltage by 10 mhz at a time, and then tested it using Furmark. I got it up to around 922 mhz with no problems, but once I started actually putting the card under load, my system started crashing. I don't get any artifacts or anything, my system just crashes. Is there something I should be doing differently? I really don't want to risk breaking something.