The difficulty of mining has quadrupled in less than two months, you're going to make far less:
Along with the earnings reduction expected from high difficulty, pool mining during the current difficulty has also been affected by bad luck. As the pool has a smaller percentage of mining vs the big ASIC farms, variability is increased. This is the nature of any pool that doesn't have PPS (with the pool owner taking all the risk), there's going to be periods with either more or less block finds than expected.
Block Date Shares Payout Share Val.
269695 11/15/13 06:09 AM 237472651 19.31342465 0.000000081
269648 11/14/13 11:02 PM 1494880017 45.70631176 0.000000031
269333 11/13/13 03:49 AM 2147483647 65.60088711 0.000000031
268847 11/10/13 02:38 PM 457268162 24.33921501 0.000000053
268756 11/10/13 01:46 AM 1479433909 47.78782646 0.000000032
268486 11/08/13 03:32 AM 964254129 24.7370004 0.000000026
268293 11/06/13 07:33 PM 2147483647 53.39340188 0.000000025
Average number of shares per block has been 1275M, whereas expected is ~difficulty of 511M. However, the DGM payment system has actually mitigated variance and luck risks, spreading miner earnings across multiple rounds, for an average per-block payout of 40.1BTC instead of 25.
You must keep separate your evaluations of miner earnings, which fluctuate due to the "lottery" nature of mining and accumulate far after you've submitted shares due to DGM delay, with issues withdrawing funds, which should happen automatically shortly after your earning threshold has been reached.
