Copied and transferred (all three files - cache and pmd included) onto the new one. Although, initially, saved a copy of the original as a different name, then, used the main copy to prepare the amended version - then, transferred - but maybe that is what created the problem???).

Noticed that even on the original one that was saved under a different name (ex. clientfile_original), Form 9325 shows that the return had been successfully e-filed, but oddly, doesn't have the Submission ID - when opening up on the new computer. In any case, keep getting the error message telling me that I cannot e-file the amended, as it was not properly e-filed to begin with - eventhough it was.