jgaf151, what was the outcome of this? I have two sapphire r9 280x's that do the same. they can't both be faulty, this is clearly software at fault.
I ended up exchanging it for a sapphire, because Newegg did not have a replacement available. The new one worked wonderfully, so in my case it was a malfunction on the card's sensor. my advice would be to exchange them if you can.