Nope not an orphan race, block already has 4 confirms. Probably something thing to do with a code change Kano did.
Firstly, and most important, yep it's a valid block 
As for the problem - it's a ckpool issue
CKDB was not the problem.
I can't see why there was a problem with it, but ckpool said
"[2017-07-26 07:58:42.642] SUBMIT BLOCK RETURNED: inconclusive"
... and as usual said nothing more.
The bitcoind debug.log shows it as a valid block and no problems.
It did however also say it was creating a new rev file during the block processing - but it was still only 159.7ms to process the block.
Slow, but not too slow.
Every node said it was accepted also.
Maybe I should use Antpool's software
Could be more reliable
Anyway - all good, I manually flagged it as OK and the block exists in the blockchain so we get paid for it
