what was your previous pool
https://www2.coinmine.pl/drk/Too big, so I wanted to go to P2Pool but I need a node nearer (I wanted to set one but I am waiting for a published one, I don't have time to lookup the settings).
try add
"no-submit-stale" : true,
"scan-time" : "60",
in your sgminer.conf
Will try tomorrow. To increase the scan-time to 60.