I gave up on my power dock in the end, there is something not right with it I am sure. In fact I had cause to plug it on just to supply 5V to an audio amp I was testing (lots of ambient noise when plugging into the Omega) and it was fine until I turned the volume up to more than 50% then it would play a sound file but in the middle reset the power and restart. This is with a 2.5A USB supply. This confirmed my suspicion that the Power dock had a problem supplying power correctly. Which explains why it would not power up the Omega by just plugging usb power into it. It would charge the battery but you had to toggle the power switch to get it to supply power to the Omega.
All in all I think the Power Dock has some design/build issues and I opted for another solution which I have to say is much nicer in the end.