An exploit has been found in the pool code, which means that some miners are submitting duplicate shares to the pools. Pool owners should update to latest code, pools that have been patched include minexmr.com, hashinvest.net, monero.crypto-pool.fr., and cryptonotepool.org.uk Other pools are currently being exploited, including moneropool.com, which means if you are mining there you will recieve ~50% xmr less than you should.

PS this is not related to the recent BCX stuff