Hi Dave,
strange you should mention that. We have a HDR1100s and been having recording issue (see my previous posts). Apart from that, my wife tells me that she is also seeing the same thing when the programs do record…The TV goes black for a few seconds but it does then come back of its own accord.
We have tried the factory reset with no success.
Sorry not much help but at least you are not the only one…
On contacting Humax they said that they have had a few recording issues (again see previous posts).
I suspect a software bug in some of the Humax 1000 series boxes..