Check your CAN cables. This usually indicates that the can cables are not "straight through", meaning pin1->pin1, pin2->pin2, etc.
You will see every other Jag work because each cable flips the signals, so after two cables, the signals are correct again.
See pages 25-26 of the
Jaguar Getting Started Guide found at
www.ti.com/jaguar. There is a diagram showing the correct orientation of the modular connectors when the cable is held flat.
-David