Fell Running - what shoes? (Sorry another shoe thread)

LadyBee

So I have a pair of Inov8 TrailRocs but they're not doing well on the mountains. I'd like to do a lot more fell running - think Brecon Beacons/Snowdonia type stuff, but my current shoes slip all over the place once they get onto the extreme stuff. What is a good decent fell running shoe, a bit waterproof, some support? Or should my current shoes do the job and I'm just rubbish offroad?! Thanks