Surface contact mesh error message in NX

[Aled87]

I am attempting to model stresses due to contact between two cylinders under an applied force, using a surface contact mesh in NX 7.0.
I am using a 3d tet mesh with contacts between the two cylinders, however when i solve the model i get an error message stating
"contact orientation vector un-defined?"

I feel i have positioned the contact points toward each other, so i dont quite know what the error is. If anyone knows how to resolve this some advice would be greatly appreciated.