Graphics 2.0 Snapshot - fast update problem?

I had some troubles when i am create a snapshot and then add a moving body inside it.

It seems that there is a problem updating the position of the body continously.

Is a bug?

local w = display.contentWidth local h = display.contentHeight local cx = display.contentCenterX local cy = display.contentCenterY local snapshot = display.newSnapshot(w,h) snapshot:translate( cx, cy ) --display.setDrawMode( "forceRender" ) --snapshot.canvasMode = "discard" local obj = display.newRect( 0, 0, 20, 20 ) obj.x = 0; obj.y = 0; snapshot.canvas:insert(obj); snapshot:invalidate("canvas") local function update() local nx, ny = obj.x, obj.y; obj.x = nx + 1; obj.y = ny + 1; snapshot:invalidate("canvas") end Runtime:addEventListener( "enterFrame", update );