Q: Migration Assistant causes reboot?

I bought a new refirb macbook pro and am trying to migrate my data from my old macbook pro. Both machines have Mavericks on it and I also have a time capsule. I bring up migration assistant , it sees the source time capsule and I am able to select the user data that I want to transfer. It starts to calculate the transfer and then the machine reboots. I tried to do the this between the two macbook pros and got the same result. I am using ethernet cables to facilitate the network and not the wireless. Why is migration assistant appear to start but then the macbook reboots? None of the data transfers to the new machine.