Hmmmm, I never use anything but steam a seam... You might try spritzing the paper backing with a little water then try to get it off... I have left the second piece of paper on mine for a looong time without problems. You don't have to leave the hot iron very long to adhere, could you have left it to long and it really setup? I'm just owndering out loud so to speak/type....
I have to stop and think when I need to reverse a pattern so it's facing the correct way up. That sometimes is a pain.
It will gunk up a iron fast if not careful with placing something over it. I use paper sacks if I have nothing else handy. I finally bought a pressing paper just for this.
Sure hope you get it to work for you. I just love the stuff.