Ship vanishes when other one fires

So in the game I have been working on, there are two ships in space that are going to fire at each other. Got the movement and shooting pretty much down, need to do some stuff like set the ships to move with different keys, but the idea is there.

I am having a problem when ship 2 (the black ship), fires using the shift key. It seems to make Ship 1 (the white one) to dissapear completely! I think it might be a problem with the depths.

If anyone can help me with this, I would be very thankful.

-JJS :block: