Not certain how you're setting your expectations? Just going by the simplest calculation of an ideal block target time of 60 seconds and a 250 FOX block reward you end up with the following for 30 minutes at 3.3 MH/s with a 250 MH/s network speed - 250*30*3.3/250 = 99 FOX per half hour. Now sure, 500 FOX in 4 hours is quite a bit short of that, but that calculation is overly optimistic regardless. Though that calculation matches up pretty much perfectly with your 66 coins per hour at 1.2 MH/s.