I just had a nice lady help me with this issue. If you go re-open your state return and click on the File button up at the top left hand corner and select 'remove state return'. You should get another dialog box to confirm you want to delete the Idaho return. You basically have to remove the state return and then start over with it. This worked for me, I hope it works for you! I was able to get all the way to the end and efile, without duplicating my federal efile.
