Hi Scott,
I'm going to ask a few scoping questions here.
1. is this VLAN used to make the layer3 keep-alive (L3KA) link?
2. if so, is the VLAN on the L2 peer-link (L2PL)?
A quick and easy way to set up VPC on N7K is to use a layer3 port, in a separate VRF...I use VRF L3KA for ease of management. I'm not a big fan of lengthy/wordy VRF-ids :-) if you're using multiple VDCs do something like vdc1-L3KA, vdc2-L3KA etc.
L3KA is loosely analagous to a starter motor on a car, it has to come up before the L2PL can initialize. If the L3KA is a L3 VLAN interface on the L2PL it'll never initialize.
--
JD