i guess it could be a bad driver might be worth trying to reinstall the drivers, if your mining litecoin it wouldn't surprise me litecoin can come up with some weird effects. i dont know if yourve over clocked the card or not but you could also try setting it back to default or maybe slightly under default see if it makes a diffrence
looking at the video again (5 seconds is very hard to go trouble shooting on) it might be the mining is using that much of your GPU that its having a hard time refreshing the screen quick enough
does it go as soon as you stop mining?
It works perfectly fine when I stop mining. I am running 4 copies of Diablo III at the same time.
The card is clocked a bit but nothing extreme - the driver should be fine as I used ATI's auto download driver software (whatever it's called).
EDIT: I am mining BC not LC.