Correct ... if you have NOT yet filed the return then when you log in you should have the option to continue the return. Once that option is gone you need to use the "back door" option to open it again ... this is a safety feature to keep users from accidentally messing up a filed return. The other option would be to amend the return if you need to make changes.
If you don't like the online system then I highly recommend using the downloaded version where you can access any return at anytime.
