Lower "I". It has been discussed many times on this thread and FAQ on main site. Lower your intensity and you can reduce rejection on your side.
I reduced I from 18 to 16 on my 7870's and have seen drastic improvement on rejection.
Other part, pool owner is working to fix his side, and from last post it appears we'll see some improvement.
Patience is virtue.
Intensity is not the problem. Mine is 34% reject ratio for 3 hours at intensity 20. Lowered intensity to 15, 52% reject ratio. Other pools 1-5% rejects.
Then go to other pools. End of story.