Thanks for so quick answer!

Well. Just couple of hours, but miner was restarted few times by me already and now I can see it just did restart itself.
But don't bother for now. I use Wifi and it's very laggy while block chain is downloaded. I'll wait for this to get completed and come back in case of any issues.

I think it gets more rejected shares just after miner startup.

BTW, my initial impression on this product is so good, so I just ordered standard box for this. Well done JStefano! Thank you for your work.