Corona SDK Physics goes on and off while object is in motion

Question

Below is my main file. essentially what is happening is that the collision is working when the "rect" object is not moving but as soon as i move the rect object, the collision stops taking affect. I think that it knows it is colliding but it does not do anything (like interaction with the objects at all). does anyone have any thoughts, why this is happening? and how to fix it?

local physics = require("physics") ; physics.start() ; physics.setGravity( 0,0 ) ; 
physics.setDrawMode( "debug" )
display.setStatusBar( display.HiddenStatusBar )
math.randomseed( os.time() )

physics.setVelocityIterations(10);
physics.setPositionIterations(20);


--set up some references and other variables
local ox, oy = math.abs(display.screenOriginX), math.abs(display.screenOriginY)
local cw, ch = display.contentWidth, display.contentHeight

--set up collision filters
local screenFilter = { categoryBits=2, maskBits=1 }
local objFilter = { categoryBits=1, maskBits=14 }
local fieldFilter = { categoryBits=4, maskBits=1 }
local magnetFilter = { categoryBits=8, maskBits=1 }

--set initial magnet pull
local magnetPull = 0.25

--set up world and background
local screenBounds = display.newRect( -ox, -oy, display.contentWidth+ox+ox, display.contentHeight+oy+oy )
screenBounds.name = "screenBounds"
screenBounds.isVisible = false ; physics.addBody( screenBounds, "static", { isSensor=true,     filter=screenFilter } )


local function newPositionVelocity( object )
    local math_random = math.random    
    local side = math_random( 1,4 ) ; local posX ; local posY ; local velX ; local velY

if ( side == 1 or side == 3 ) then
    posX = math_random(0,display.pixelHeight)
    velX = math_random( -10,10 ) * 5
    if ( side == 1 ) then posY = -oy-40 ; velY = math_random( 8,18 ) * 16
    else posY = display.contentHeight+oy+40 ; velY = math_random( 8,16 ) * -16
    end
else
    posY = math_random(0,display.pixelWidth)
    velY = math_random( -10,10 ) * 5
    if ( side == 4 ) then posX = -ox-40 ; velX = math_random( 8,16 ) * 16
    else posX = display.contentWidth+ox+40 ; velX = math_random( 8,16 ) * -16
    end
end
object.x = posX ; object.y = posY
object:setLinearVelocity( velX, velY )
object.angularVelocity = math_random( -3,3 ) * 40
object.alpha = 1

end

local rect = display.newRect(100,100,100,60);
local offset = 250
rect.x = cw/2;
rect.y = ch/2-offset;
--rect.xReference = 40;
rect.yReference = offset;



local function objectCollide( self, event )
local otherName = event.other.name
print(event.other.name);

local function onDelay( event )
    local action = ""
    if ( event.source ) then action = event.source.action ; timer.cancel( event.source ) end

    if ( action == "makeJoint" ) then
        self.hasJoint = true
        self.touchJoint = physics.newJoint( "touch", self, self.x, self.y )
        self.touchJoint.frequency = magnetPull
        self.touchJoint.dampingRatio = 0.0
        self.touchJoint:setTarget( 512, 384 )
    elseif ( action == "leftField" ) then
        self.hasJoint = false ; self.touchJoint:removeSelf() ; self.touchJoint = nil
    else
        if ( self.hasJoint == true ) then self.hasJoint = false ; self.touchJoint:removeSelf() ; self.touchJoint = nil end
        newPositionVelocity( self )
    end
end

if ( event.phase == "ended" and otherName == "screenBounds" ) then
    local tr = timer.performWithDelay( 10, onDelay ) ; tr.action = "leftScreen"
elseif ( event.phase == "began" and otherName == "magnet" ) then
    transition.to( self, { time=400, alpha=0, onComplete=onDelay } )
elseif ( event.phase == "began" and otherName == "field" and self.hasJoint == false ) then
    local tr = timer.performWithDelay( 10, onDelay ) ; tr.action = "makeJoint"
elseif ( event.phase == "ended" and otherName == "field" and self.hasJoint == true ) then
    local tr = timer.performWithDelay( 10, onDelay ) ; tr.action = "leftField"
end


end



local function setupWorld()

for i=1, 20 do
    local obj = display.newCircle(0,0, 12 )
    physics.addBody( obj, "dynamic", { bounce=.3, radius=12, density = .2 --[[,filter=objFilter]] } )
    obj. isBullet = true;
            newPositionVelocity( obj )
    obj.hasJoint = false
    obj.collision = objectCollide ; obj:addEventListener( "collision", obj )
end

local field = display.newCircle(cw/2, ch/2, 320); 
    field.alpha = 0.2;
field.name = "field";
field.x = display.contentCenterX ; field.y = display.contentCenterY;
physics.addBody( field, "static", { isSensor=true, radius=320, filter=fieldFilter });

magnet = display.newCircle(cw/2, ch/2, 40 )
magnet.name = "magnet"
magnet.x = display.contentCenterX ; magnet.y = display.contentCenterY
physics.addBody( magnet, "static", { bounce=0, radius=40, filter=magnetFilter } )

  end

 setupWorld()
 physics.addBody(rect,"kinematic", { bounce = 1, density = 1})


 deg = 0.0;
 prevY = 0;
 local function onTouch(event)
 if event.phase == "began" then
  prevY = event.y
end
if (deg<=360) then
  deg=0;
end

if(event.y >= prevY) then
   deg = deg + 10;
elseif(event.y <= prevY) then
   deg = deg -10;
end  
prevY = event.y

rect:rotate(deg);

end


Runtime:addEventListener("touch", onTouch);

Answer 1

kinematic bodies don't generate collisions. It needs to be dynamic.

Answer 2

It sounds like your body is going to sleep.

http://developer.coronalabs.com/content/game-edition-physics-bodies#body.isSleepingAllowed

Try:

rect.isSleepingAllowed = false