I am not sure what causes this, but I see a lot of variation in the DGM Estimate for workers who have been mining since the beginning of this round.  They all have similar shares, PPS, and hash rate, but 0.031 to 0.088 for the DGM Estimate.  Can anyone explain why this is?

Rank  Id             DGM Estimate   PPS             Shares         Rate (MHash/s)
.
.
.
26     b1370967    0.08870520    0.00023902    1,258,032    189,418
27     92ca6782    0.07987875    0.00023875    1,256,624    186,745
28     1c5ecddf    0.03129269       0.00023657    1,245,148    193,025
29     50617a48    0.07995814    0.00023484    1,236,000    187,547
30     e4f4a935    0.03138867       0.00022465    1,182,384    180,102
.
.
.