I'm experiencing high rejected shares with your miner, currently on 12 rejected shares with 167 accepted, is that common or maybe you have any insight?
My setting is a low noise one with -40% Powlim, -100 mV through recent afterburner update, and 800Mhz Mcloclk with 1584 H/s avg and 1700 peak,
Are the rejected shortly (1-2 seconds) after a new job was received? Something like this:
[08:11:00] New job received. Avg Job Time: 15.7 sec
[08:11:00] Difficulty changed. Now: 40000.
[08:11:01] Found Nonce, submitting...
[08:11:01] !Rejected, Nonce Invalid!
Then the reason is that there is already a new job and the calculated nonce are from the previous job.
A roundtrip takes 1-2 seconds in the GPU, an improvement would be to faster cancel the current job and throw the old results away. Currently it tries to submit them. Will try to fix in the next update.