I read that other people also having this problem sometimes, but now i'm experienced this myself.
One of my miners config is suddenly changed to

stratum+tcp://bj.ltc1btc.com:9999   pcfli.nm
stratum+tcp://stratum.f2pool.com:3333   pcfli2.nm
stratum+tcp://stratum.mining.eligius.st:3334   1GwHVTfV3cGMkZXFF36fhzhNbPhyy7TcQr

From the pool hashrate graph it looks like this event was around 12hrs ago.
I already submitted now the pool settings change request on that miner, but also would like to know how this event would be compensated.