If you saw a bedliner peeling away it was probably a self installed herculiner or possibly, because Line-X's properties it is virtually impossible for it to peel, even with a bad prep job. As for trapping moisture, that is IMPOSSIBLE, CANNOT HAPPEN, sorry. First it bonds directly to the bed, no moisture can get in, SECONDLY even if there was moisture in the bed when it was sprayed, it wouldn't rust, you need air to rust and Line-X is air tight, simple chemistry proves that wrong.