Pro tools CPU error message

So when ever i enable my play back engine to my interface (saffire Pro 40) i get a CPU Error 6101. However if i change my playback setting to the computer internal listening card i can run all my sessions any ideas why my interface might not be working. It doesnt matter how many tracks i have going in the session either, i can be running a blank session with one armed track and it gives me the error message.

Are you on 10.3? Ever since updating to 10.3, I've been getting relentless -9171 and -9172 messages even on 1 or 2 track sessions!!

do you have latest saffire drivers ? mac or pc ?

Im running my pro tools ten on a Imac OSX 10.6.8. Pro Tools 10.0.1