Images doesn´t appear in storyboard Corona SDK - lua

Question

I am doing a game in corona SDK, but I have this little problem.
I have a menu with a button. If I press it, it sends me to the first level of my game.
When I pass the final level, the game return me to the menu. Bur, if I start playing the first again, my images doesn´t appear.
The images are balls, and to pass the level, you have to eliminate all the balls. To do this, I use:
ball:removeSlef()
ball = nil
But, I don´t think that this is the problem, because I eliminate this lines, and it doesn´t work.
The images are create in scene:createScene function, and insert in the Group.
I short the code of the first level to be understood.
local storyboard = require( "storyboard" )
local scene = storyboard.newScene()
local physics = require "physics"
physics.start(); physics.pause()
physics.setGravity( 0, 0 )
local cont = 0
local bur = {}
function eliminar1( event )
if (cont == 0) and (event.phase == "began") then
event.target:removeSelf()
bur[1] = nil
cont = cont + 1
end
end
function eliminar2( event )
if (cont == 1) and (event.phase == "began") then
bur[2]:removeSelf()
bur[2] = nil
cont = cont + 1
end
end
function eliminar3( event )
if (cont == 2) and (event.phase == "began") then
bur[3]:removeSelf()
bur[3] = nil
storyboard.gotoScene( "levels.1.level2" )
end
end
function scene:createScene ( event )
local screenGroup = self.view
for i = 1,3 do
bur[i] = display.newImage("irudiak/"..i..".png")
bur[i]:translate(math.random(0,280), math.random(0,400) )
physics.addBody( bur[i], {bounce = 0.3 } )
bur[i]:setLinearVelocity(math.random(-50,50), math.random(-50,50) )
screenGroup:insert(bur[i])
end
bur[1]:addEventListener("touch", eliminar1)
bur[2]:addEventListener("touch", eliminar2)
bur[3]:addEventListener("touch", eliminar3)
end
function scene:enterScene( event )
local screenGroup = self.view
physics.start()
end
function scene:exitScene( event )
local screenGroup = self.view
physics.stop()
end
function scene:destroyScene( event )
local screenGroup = self.view
package.loaded[physics] = nil
physics = nil
end
return scene

Answer 1

createScene is ran only first time when you gotoScene. Every next time only willEnterScene and enterScene are played. To play createScene again you have to remove it (storyboard.removeScene() I guess). Or you can move some stuff you need to willEnterScene. For more detailed info you can watch this: http://www.coronalabs.com/blog/2013/08/20/tutorial-reloading-storyboard-scenes/