noob question: a few weeks back my 950H/s setup was getting about 0.1ZEC about every 3 hours on flypool. These days I am getting only 0.1ZEC every 5-6 hours. What would cause this? Increased difficulty?
Yes, the difficulty going up means it takes longer for the pool to find blocks. Less blocks found means less frequent payouts. You aren't getting 0.1 ZEC every 6 hours or even every 24 hours with 950H. With that hashrate you can expect about half that in 24 hours.