Pool users should check their connections to Slush. I noticed with two miners that I hadn't submitted a share in the last ten minutes. My miners were showing that they were still connected to pool 0, but 46.28.205.80 instead of the normal address. There is talk on Eligius about a malicious player doing a man in the middle attack, it's worth reading up on.
I had this problem about 3 times in last few days. 15 minutes ago my both antminers were submitting work and nothing looked different, but for about one hour they were sending results somewhere else, because slush pool was reporting 0 shares. After reconnection everything is ok again... I really hate how many thieves are attracted around bitcoin.
Has happening twice to me so far. Same IP. Bah!!!!