Slush always has consistent luck, about 6 blocks a day average. I think they got DDOS'd yesterday. They payouts are increasing back up to normal.
DDoS attack sounds like a good explanation to me. Very strange when I saw that happen (and one of my S1's had a best share of around 453,xxxx,xxxx).
Anyhow, I have to see out my shift on the P2Pool node I switched to, plus that jump from 6PH to 9PH on the pool will definitely reduce my earnings .... so will see when we are done here.
p2pool is the right move; using is own p2pool node gets all the advantages of local mining, with the huge hashrate of all nodes.