Strange, maybe just bad luck. I'm solo mining since about 08:00 GMT on a single i5-3570K CPU @ 3.4.
Using the stock client on Ubuntu. Got 8 blocks, 4 of them stale. The other 4 resulted in 132 Coins.
In yacoin.conf I added:

maxconnections=256

To spread the word (block) as fast as possible. I also configured my router to forward port 7688 to the PC. Most connections are incoming.

However difficulty has increased meanwhile and the last block was more than 6h ago (14:44 GMT). I keep it running.