Well I think you were lucky you never had that with 0.31. The new watchdog script detects this graphical error messages, kills everything and should be able to get it back to live.
Well apparently, I did experience this in 0.31 that's why I switched to 0.34 thinking maybe it will solve the issue.
What I am saying that I had no problem with 0.31 mining only with HD 5770. But when I am mining together with R9 280x, the problem occur. So I switched to 0.34 hoping the issue will be solved. And no, the watchdog didn't restart the miner. I had to click the cancel button in order for the miner to be restarted. It sucks when this kind of error occur while I am sleeping, my miner got to be idle for a long period of time.