This box is definitely new (Directv H10 manufactured by Samsung) - as Best Buy *just* received these in within the past couple months I believe. I could be a little off on this ... because sometimes Best Lie is a little behind on their equipment ... but it hasn't been out for more than 1-year ... because they still had the old Samsung HD Receiver (360?) on the shelf for display clearing it out.
I called DirecTV Customer Service - and the girl, who was very nice and helpful named Tammy, ONCE I got to the '*Advanced Technical Support* for Advanced Receivers (not the first-level DirecTV rep I spoke with), said that this *WAS* a known issue with the black 'flicker' on the HDMI port for about 1-2 seconds - but that the issue has only been brought to their attention within the past week or so.
She said that she *HAD* replaced several customers receivers when it first started - but that this is definitely software related - and it's like the HDMI port/software is not totally 'syncing' (or staying synched) with the TV. She said there will be a software fix for this released somewhere around mid-June that should take care of this - and that we could use the Component Cables in the meantime to remedy the situation if we wanted - or just continue using the HDMI with the annoying flicker.
I told her my concern was - I didn't mind waiting on the software fix - but since I just purchased this receiver, and it was still in warranty, I didn't want to wait for the fix and then still not have it working properly IF the fix didn't work. She said that if that happened, DirecTV would replace the receiver free of charge. I had her note this on my account just in case. So, to all having this problem, it's likely NOT your cable.
And on a side note, the first Directv girl I talked to (in regular support) argued with me that 'this was not an issue with this receiver'. So just make sure you are passed onto ADVANCED Technical support since this is a HD Receiver - and don't listen to any 'this is not an issue' non-sense. I don't think we're all crazy here. (or we could be but who would know eh?)
Good luck and please report your results here.
Thanks,
Dabos