Try wafflepool instead of just going back to middlecoin... Then watch your rejects drop to almost nothing, and profits increase along side.
How they manage to do that?
More servers + lower share difficulties.
I checked the profit average from 2/5 to 2/17 from both sites (biggest window provided by wafflepool) and found
Wafflepool range average = 0.010807 btc/Mh/24hour
Clevermining range average = 0.010903 btc/Mh/24hour
While clevermining has +10% rejects, and wafflepool has <1% rejects.....Wafflepool is the clear winner atm.