I personally have a measly 20m/h from a contract a few months back.  My calculations seem to show that I should still be getting small mining payments.  I have had payments that have come in smaller than what I was getting lately too, as I had originally been mining other coins with the contract as well, so I dont think the hashrate is too low to generate a minimum payment.  I might be wrong, but people mentioned that they are missing payments on almost the exact same days that I am, and some of those people have more hashrate.  I could be victim to the mining difficulty raising too high, but from using mining calculators, it seems I should still be getting small payments.  Its not enough for a payout each day, but it was originally paying out roughly every two weeks.