Just an update for everyone using this as reference.
So I made outlines of a fireball and a ramp in my game, using graphics.newOutline. I also made a bunch of other outlines on other things like a fire monster and a snake monster. So on the corona simulator all the outlines were there and the collision detection was perfect. On android, most of the outlines worked, but the fireball and the ramp had no collision detection what so ever, physics bodies would just go through them. So since these two weren’t very difficult shapes, I ended up just drawing a shape over them using the shape parameter when you create a physics body, which worked on the device.
As far as errors go, I checked for case errors and there was nothing. I also changed the picture but kept the same name, and the same thing happened, worked on the simulator but not on the device.
So I guess if this is happening to you and you’re pressed for time, you may as well just take the time to draw a shape around your picture for collision detection.
Thanks everyone for your help.