I have already had at least 20 times contact with DM abou my HDMI related problem.
DM have even asked me to send the box, but I got it back without them changing anything to it .... so I only lost money for the transport costs !
DM was claiming that they haven't seen the problem, even after a throughout test (at my side it happens within at least 30 minutes).
They also claim, that they were not aware of the problem and that I was more or less the only one !
Suddenly after a couple of weeks I got a request from DM to test different FW's, which didn't solve the problem unfortunately until now.
The problem starts each time after about 20-30 minutes and than HDMI signal gots interuppted up to about each minute !
I have two DM800HD's and a DM8000 and only one DM800HD does have that problem, no matter to which of my three tv's I do connect it.
Both DM800HD's are more or less the same age ....
Maybe it might be important ... I mainly watch channels via the provider "Canal Digitaal"