I have same issue on my pool :(
Using latest darkcoind and p2pool (fac408d-dirty) too.
2014-07-03 18:09:37.667014 Requesting parent share bfee4f13 from 23.239.28.247:42400
2014-07-03 18:09:37.889686 > Share check failed: 0000000066f7d0dab55a481c0cdcd9e16c46341701674c70c11e5a127f461073 ->...