As I stated before if you were mining Phi there were stratum server issues not adjusting the vardiff which had a big impact on speeds accepted by the pool.
I ran into the same thing. Was mining phi but receiving no payouts. I looked at the pool stats and it had been over 6 hrs since anything had been discovered and looked like the MH/s rate of the pool was in the dumps. something like 2-3 day TTF for the block. I unchecked PHI and things went back to normal.