Could you publish the pool reject rate? Even middlecoin does that. Mine went up a lot several days ago and has stayed there (especially vardiff share above target rejects).
I used to get about 0.0%-0.1% rejects with vardiff since i mine at low intensity and am near an endpoint.
i mined almost 2 days and
41103 total accepted shares
241 total invalid shares
0.583% farm wide reject ratio