error: "the submission is a duplicate of one that was previously recieved"

I bought turbotax home and business mac download. I filed one child's return and it was successful. The second one gave the error:  "Transmission failed. The submission is a duplicate of one that was already received."

The file is completely different from the first. I have shut down and cold booted,used a different IP.

When I purchased I read I can submit up to five returns for five different people.

Thanks for any insight or suggestions:).