A Dependent SSN in the return must not be the same as the Primary or Spouse SSN on another return where 'PrimaryClaimAsDependentInd' or 'SpouseClaimAsDependentInd' is not checked.

My son did not originally check the "Someone can claim your spouse as a dependent" so my return was originally rejected.  He amended his return with that box checked.  His amended return has been accepted, so I resubmitted my tax return electronically but it was just rejected again.  How do I get around this - do I need to mail my return instead of filing electronically now?