Just worrying now about a 51% attack? Hasnt 1GH been 70-90% of the hashrate since.. forever now?
Try restarting your daemon. It will stuck.
Even you connect to the right peer with working peers.
I see proof-of-work error on debug.log when submitting blocks. It will be not easy for testing for you since our pool is handling GH to test on submitting block.
It can't be explained that submitting block is failed even on fork.
I even tried checkpointenforce=0, -disablesafemode but no luck.
You know that checkpoint had bug even before hardfork. Just get rid of it and revert. I don't understand why maxcoin needs checkpoint resync.
What proof of work error are you getting? Are you still trying to create blocks with a coinbase of 48?
We need checkpointing due to the increased risk of 51% attacks in the event that our hashrate drops following a decrease in reward.