Do you have a USB protocol analyzer hardware? You could capture traces of the two failing conditions and analyze to see where exactly the enumeration is going wrong.
What exactly happens when you connect the device in the failure case? Do you see your device in Device Manager?
Does it come up with a valid VID/PID? What error code does it show, if any?
Since you say that all combinations work on the DVK, this could be an issue with the electrical signalling on your board. But you also mentioned that vendor code 0x01 works on 8.1 but not on 7. And vendor code 0xAB works on 7 but not on 8.1. This behvaiour is not consistent to support the board/hardware issue theory.
You could try to experiment with a completely new vendor code. Also try a completely new combination of device vid/pid (basically enumerate it as a totally new device to the PC).
Analyzing USB traces here would be helpful.