It's an orphan I'd say. It was mined but there was someone else who submitted the block quicker than I did so my block was rejected. I get maybe one or two every couple of weeks. When difficulty is lower than 500, I see one get orphaned. Above 500 and I see not one orphan, all are accepted into the blockchain, rewards are much higher like the 3k block that was orphaned. 400 and below diff, I see maybe 2 or 3 orphans every few days, rewards are also much smaller but alot more frequent than when diff is above 500.


I have 83 million coins staking. Since POS began, I've always had big and frequent stakes. Despite that 10% of my coins had not reached stake age yet, the other 90% of coins were untouched. They are now all staking well past their 30 day cut off. I should also mention that at any given time I have on average, 90% of coins going to stake regularly, infact each time I mine a block almost all my coins move into stake


I have two wallets for this very reason. On my home LAN, my desktop PC hosts my stake wallet with the 83m coins. It stays open and running 24/7 as does my desktop PC. Only coins going into that wallet, none coming out. I have a 'spending' wallet hosted on my mining rig that's mining on the pandacoin multipool. It holds all my payouts from the multipool and any other coins I 'collect' in prep for a move to Mintpal or another exchange or move more coins into stake.... I never mix the two... This makes it a hell of a lot easier to manage which address sends what coins to where and guarantees that I don't mess up coin ages and losing potential stake rewards by sending from the wrong address.