"Total reward: Unconfirmed + Confirmed " is frequently going down, thought it was me miss reading at first but it is happening, anybody know why?
You see this when a block becomes orphaned - recently we have had a few - last 2 were blocks 233158 and 233303. Before they are marked as orphaned, you see them adding to your total. Then when they are marked as orphaned, your total goes down by the amount you would have earned for that block.
Read more about orphaned blocks here
https://en.bitcoin.it/wiki/Block_chain