I´m seeing very low profitability. I have 6.1 MH/s (steady, with a 0.5 to 1% reject rate) pointed at coinfu, and yesterday´s payment was 0.02017, or 0.00331 BTC per MH/d. that is very short from the latest profitability numbers posted (0.004621 btc/mh/day) Any idea what could be the issue?