Dissapear with delete

Simple but confusing problem, I have 3 masked layers (each with they’re own mask), one set is text, two sets are graphics. I also have a BG layer under all this which I need to get rid of, but the problem is that whenever I delete the bg layer everything else except for the bottom-most graphic becomes invisible and unselectable. Like they don’t exist, except they still show on the timeline, their tweens and keyframes and everything.

Anyone know what is going on? Flash glitch?