The unit has only been in operation a few days, so I am still finding my feet.
When I play some of the recordings I've made, the picture and sound break up, making them unwatchable. But other recordings (the majority?, the most recent?) are OK.
The problem affects recordings I have made from BBC1, BBC2, C4, but I believe I have had good recordings from these channels, too (certainly from BBC2 and C4).
In one case, I had recordings from programmes that were broadcast consecutively (episodes of The Simpsons last Sunday), the first of which was corrupted, the second wasn't.
I can watch live tv without problem. The tv is a Sony Bravia KDL-32D3000 (2007 or later).
When I first set up the 4000, I had a blank screen and an error message along the lines of "This tv won't display the content because it is not fitted with HDCP". (A situation on which the instruction booklet was blissfully silent.)
Trawling the web, I found a Sony site which (amazingly) recommended that I unplug the Humax, wait 30 seconds and plug it in again. (Amazingly) this worked. I still get the message, but the tv goes ahead anyway and shows whatever the Humax feeds it. (I am obviously watching SD channels only, though I can see HD ones too.)
I assume HDCP is a red herring because it only applies to HD, but there appears there might be some sort of "handshake" problem.
I don't know whether the tv has HDCP installed or not and, if it does, whether it has the most recent version. Or whether this is at all relevant.
I leave the Humax switched on all the time. (Sometimes the light goes red = standby, but it carries on recording anyway.)
I switch the tv to standby when I have finished watching it.