You can always check the BIOS number at present by using GPU-Z. If you download the correct update file and then point @BIOS to it you will make sure that you have the correct one.
I have done some more reading on other forums and maybe it is my cheap £20 alpine 750w power supply that is the problem for the card crashing in games and furmark test.
I would suggest that you change that PSU anyway as soon as possible before you end up having to change everything! Never buy a cheap and nasty power supply they can go wrong and take out all you other expensive components at the same time. Not only that just because it is marked 600W often they are nowhere near that rating. Purchase a good make like Seasonic, CWT, Corsair, Thermaltake, Enermax, Gigabyte, Coolermaster, Antec, etc and try and get one with a single 12V rail if possible. I would advise you to get one of about 650W minimum depending on your hardware demands.