My State of Illinois e-filed return was also rejected- despite confirming that the prior year's AGI was correct as entered, and checking everything else. There were no data entry errors, and I was not able to figure out why it was rejected. I printed it out and will mail in. I think there's a problem with either Turbotax or with the State of Illinois authentication, since the fields I entered for e-file validation (past years AGI, PIN #s with the state, etc) were correct.
