I'm just going through this nightmare of ill preparation of the walls prior to papering. I used DIF and all those special gadgets and it's still messed up! I've got 1 to 3 layers of paper missing and now I'm not sure what to do other than mud and re-surface the all walls. This is in one bathroom and I have more to go and I'm not looking forward to it because I'm sure they did the same in the other rooms. Any suggestions on how to "fix" my walls?