It generally rejects shares. But sometimes accepts;

2014-03-13 23:18:25,346 INFO proxy stratum_listener.submit # [409ms] Share from 'Xhw8EQDdK4ogGFre677vgh4RYkocLafQPp' REJECTED: (-2, u'Share is above target', None)
2014-03-13 23:18:25,674 INFO proxy stratum_listener.submit # [409ms] Share from 'Xhw8EQDdK4ogGFre677vgh4RYkocLafQPp' REJECTED: (-2, u'Share is above target', None)
2014-03-13 23:18:26,002 INFO proxy stratum_listener.submit # [409ms] Share from 'Xhw8EQDdK4ogGFre677vgh4RYkocLafQPp' accepted, diff 0
2014-03-13 23:18:31,435 INFO proxy stratum_listener.submit # [409ms] Share from 'Xhw8EQDdK4ogGFre677vgh4RYkocLafQPp' REJECTED: (-2, u'Share is above target', None)
2014-03-13 23:18:33,763 INFO proxy client_service.handle_event # New job 461 for prevhash bf247f26, clean_jobs=False


I set diff 0.001