ctr-z glitch?

[Toasterman]

While working, I accidentally moved one of the walls in my game and pressed ctr-z to move it back-
it moved the wall back where it was, but it also removed the actor's animation and all of it's clone's animations (10-15 of them)
I was using a sequence, and the sequence no longer shows up in the actor's list of animations (so I cant apply it to the actors again) yet when I try to replace the sequence with another identical one, it doesn't show up either

I didn't save and rebooted the program, but the animation still doesn't show up-
anyone had this problem?
any way to fix it?

[lcl]

I've had same problem. I don't remember how I get away from it...
But, if you want to lock actors so you can't move them by accident, click actor with right
mouse button and select lock actor.