Corona SDK PurgeScene destroys physics - lua

Question

I have create a simple scrolling game, following closely to Mark Farkland's Game tutorial. I clearly followed his coding pattern but got to the point where I am just lost and don't why mine behaves different that his example. Everything is working fine until after a scene is purged.
I have two lua files: game.lua and gameover.lua. In game.lua exitScene I have removed all the eventlisteners. In gameover.lua enterScene, I have purged game.lua scene. When the user touched the screen it then loads game.lua file. Every objects load and refreshes like new apart from the main object which just shoots upwards.
Game.lua
local storyboard = require("storyboard")
local scene = storyboard.newScene()
local physics = require("physics")
function scene:createScene(event)
physics.start()
....
local jet = display.newImage("images/jet_normal.png")
physics.addBody(jet, "dynamic", {density=.07, bounce=0.1, friction=.2, radius=12})
local activateJets = function(self, event)
self:applyForce(0, -1.5, self.x, self.y)
end
function touchScreen(event)
local phase = event.phase
if phase == "began" then
jet.enterFrame = activateJets
Runtime:addEventListener("enterFrame", jet)
end
if phase == "ended" then
Runtime:removeEventListener("enterFrame", jet)
end
end
Runtime:addEventListener("touch", touchScreen)
end
function scene:exitScene(event)
Runtime:removeEventListener("touch", touchScreen)
Runtime:removeEventListener("enterFrame", enemy1)
Runtime:removeEventListener("collision", onColission)
end
GameOver.lua
function start(event)
if event.phase == "began" then
storyboard.gotoScene("game", "fade", 100)
end
end
function scene:enterScene(event)
storyboard.purgeAll("game")
background:addEventListener("touch", start)
end
function scene:exitScene(event)
background:removeEventListener("touch", start)
end

Answer 1

You need to add the jet to the current group.
function scene:createScene(event)
local group = self.view
--...
local jet = display.newImage("images/jet_normal.png")
--...
group:insert(jet)
Runtime:addEventListener("touch", touchScreen)
end
The proper cleanup will happen to the group when exitScene is triggered.
more info / different implementation:
http://docs.coronalabs.com/guide/graphics/group.html