Hello Marc,
I heard you are in contact with the territory team. They should be able to help you with this issue, but I wanted to make sure we closed the loop. The issue is (almost always) that the Network that the DHCP Range is part of is not assigned to the 2 nodes that are part of the DHCP failover association. Another common issue is that the you have gone thru all the steps and then not turned on the DHCP service on both members. Please let me know if you are continuing to have issues. I would be more than happy to assist.
Thanks,
Mark