Answer from MRR about connectivity to Zpool.ca :

We have reviewed this rental and canceled the remaining time.

Your pool, sha256.mine.zpool.ca:3333 would not accept connection.

Thank you for using MRR!

--- That would be everyday then, and this i dont understand. With  my own miners, their check gives a warning, as it does with all other miningpools.
--- Reported this, and eventually got some miners (with S9's) with the same problem.

Or it mines at half speed, and gives errors. Or it mines normally, but also with the pool check error.

So if Zpool/crackfoo can inspect if he accidently blocked MRR-pool check routine, and make clear problem is not with them, then MRR can lookup their part.

Thanks in advance.

DS-M/Sander

* Update : Seems to problem was fixed today, somehow.