New Sapphire R9-280X Toxic - artefacts even when not mining

Hi all,

Received delivery of my new R9-280X Toxic yesterday, and I've had problems with artefacts since. Weird coloured squares randomly appearing on the screen, also happens while gaming, and most importantly also happens when NOT mining. Idle temps are approx 21C, and I have not seen a higher temp than 70C even when mining.

I should clarify that the card is mining like a boss - the very first config file I tried, copied and pasted from these forums (don't have it on me, but TC=8192, I=13 iirc) got me hashing at 782KHash.

If it helps, it's the 041 BIOS version. I know there's an upgrade to the 043 version, but I have read that it significantly lowers hash rate - I am not even sure if that upgrade is open to me, as the VRAM used on the newer models is different.

The card is seated (firmly) in a PCIe 16x slot on an Asus P8P67m Pro mobo. The PSU is a 750W Corsair Gold.

Is this an RMA job? Or is it possibly something silly I am missing?

Any help appreciated!

Rit.