Please Help - Open Ground on Monster Power HTPS 7000

[Zorlac]

I just bought a used Monster Power HTPS 7000 for cheap. It is pristine and less than a few years old. It has six outlet banks on the back. The video, digital and analog banks (four out of six banks) share the ground via a grounding rod that is connected to a wire that is connected to the chassis. The video bank shows as correctly wired with an outlet tester, but the two digital banks and the one analog bank show open ground. Everything thing looks perfect inside. The grounding rod doesnt move and the solder joints look great.
 
Any ideas what is going on??? Are these banks supposed to show open ground??
 
Here are pics from Monster's site for reference:
 
http://www.monstercable.com/productdisplay.asp?pin=3409
 
And here is an actual picture of mine inside...starting from the right, the first 3 banks are open ground and the 4th is correctly wired, yet they all share the same grounding rod.
 

 

[Zorlac]

Im starting to think this is by design. The wiring schematic that Monster prints on the top case cover shows AC power going through two isolation transformers for these three banks only.

 

[Zorlac]

This is by design. I verified with Monster and also found someone else with the same unit and they show the same open ground with the isolated outlets only.