I could not seem to add electric walls to R1 either. Even IF I copy one that's already working. If I take one that's already there and move it to the screen I want I think that worked.. can't remember.
Are these crashes in the editor, or the game? Cause the game crashes are out of my control, if you give it a bad level then or anything it doesn't like then it will just crash.
I might give eletric walls a try now, BTW some things are hard coded NOT to work in certain levels.
Edit: See screen shot
I moved them from the bottom screen, but the walls didnt appear until I died! So perhaps you can't have them in the first screen?