No good ideas, but having the same issue. In trying 800 MHz and 900MHz each separately for about 24 hours, I received even lower hash rates on CM.
I'm running 20 Gridseeds, RaPi, and CGMiner 3.7.2 showing ~7.2Mh/s on miner, but only showing up ~5.0Mh/s on CM. That puts each GS averaging about 250 Kh/s on CM, but showing 360 Kh/s on CGMiner. My GS have fairly equal accepted work, are mining pretty efficiently at 850 MHz, with minimal (0-3) HW errors per unit per 24 hours. Reject rate is just over 1%.
I'd too would like comments back if others are experiencing lower hash rates on CM and any tweeks or adjustments to increase real, recognized hash rates on CM. Hey - not complaining though - with the recent ~200% returns, it was like getting real 500 KH/s from each GS!
Thanks for a great pool and the professional efforts/information from everyone!
I have the same issue, but it is only a recent issue (it was not present last week). I tried several other sites and the problem only appears on CM. CGminer show 10.8 MH/s, on WP I get around 10.5 average, on other pools well over 10. On CM I get a bit over 8 on average. So about 85% of my hash rate. Rejects are really low, 1-1.5%.