just that one return? I saw someone else that had one of those say they did Save As and gave it a new name and then it went with no problem...no clue how or why that would make a difference but could be an easy fix.

Once you Save As, you'll have 2 returns with the same SSN in the EFCenter, you'll need to open the original one and uncheck the EF boxes for fed and state (and switch over to the state return for that to "take" then exit/save) to get that duplicate SSN message to go away