I also occasionally experience random failures after sleep, or when its supposed to go into sleep state. After such failures i need to unplug the power, after which it reports that "the overclock failed". I guess it has something to do with this platform.
Only occurs once or twice every month, so it doesnt really bug me, but still.
I'm currently using the pre-last bios version, since there was a new one released a few weeks ago. Perhaps the newest bios solves these problems(it does say that it improves stability), but I doubt it.