After 9 hours of runtime p2pool shows:
693MH/s in 41521 shares Recent: 10.93% >75MH/s Shares: 645 (112 stale)
And Diablo Miner shows:Pool:
mhash: 101,5/101,7 | accept: 645 | reject: 0 | hw error: 5
So 112 of 645 shares are stale shares this is a 17,4% stale rate.
Something is still wrong and i don't know the root cause.