Boinc stopped crunching cuda today

For some reason my client stopped crunching cuda. The cpu is still crunching.
I have plenty of work for it to crunch, but it won't.
I have not made any changes in the settings, "use gpu always".
It has one waiting to run and all the others read to start.
My gpu still plays my pc games with no problem.
What gives.?

EDIT..

It had not processed any cuda units for the past 8 hours.
But for some reason it just now started crunching again.