Ok,
So, I've 3 machines with aprox. 6.6 HPS total and got 4/4 Stale blocks.
yago@linux64 ~ $ grep generated ~/.protoshares/debug.log
generated 50.00
ERROR: ProtoSharesMiner : generated block is stale
generated 50.00
ERROR: ProtoSharesMiner : generated block is stale
generated 47.50
ERROR: ProtoSharesMiner : generated block is stale
generated 45.125
ERROR: ProtoSharesMiner : generated block is stale
Still no good blocks
Maybe I'm doing something wrong?