I've looked up everywhere but haven't been able to find a solution to my problem, this is the scenario:

My provider is giving me a routed network connecting both a RB750 and a Cisco 3725, what I do is create a GRE tunnel between those two over my providers network, I configure BGP and LDP over that and both routers see each other as BGP and LDP peers.

Then I create a VRF, both routers share routes properly I can see that because the routing table of both for that VRF is correct.

Heres my problem:

One customer connected locally to the cisco in that VRF can't ping the other customer connected locally to the RB in the same VRF and the other way around. I checked the routes in both sites and both routers but can't find a reason for the lack of communication.

I tried connecting both routers WANs directly in the same network and then both customers can see each other normally which leads me to believe that I'm maybe missing something, any thoughts?