Whats your hashrate? I've found five blocks in about 7 hours.
I have a computer that gets me 280 kh/s, an other 40 Kh/s and the last 20Kh/s, i expected to find blocks every 2 hours or so with 280 kh/s but I might be on a bad luck block.
Maybe that's it. I have one doing 350 and two doing 100 each.