Scratch

Hey alll.... im completley stuck and as much i was convinced i will manage it myself i decided that i cant kill my mind for any longer... 

So im doing this awesome project of 120 balls (1 at the time) falling true the peg of many cubes and each time or most of the times the path is different. So whenever the ball reached the edge it leaves a stamp. In case there is another ball falling into the same point the ball should stay on top of the other ball by changing the position lets say y 10...
so i got the thing working to the part that i get 2 balls on top of each other by using the block of #If touching the (color)# but for some kind of reason every other ball what falls to the same point dosent stop on top but falls to edge.. 

Here is the scrip...it would be great if someone could have a quick look and could suggest me what em i doing wrong.. Thanks upfrony 

when_green_flag_clicked
{
   clear
   repeat 120 
   {
      go_to_x: 0 y: 170
      show
      repeat 8 
      {
         repeat_until (touching_color [FF0000]?) 
         {
            change_y_by -1
         }
         set whichWay to (pick_random 1 to 2)
         if (whichWay = 1)
         {
            move -10 steps
         }
         if (whichWay = 2)
         {
            move 10 steps
         }
      }
      repeat_until ((y_position) = -175) 
      {
         change_y_by -1
      }
      if (touching_color [0042FF]?)
      {
         change_y_by 10
         stamp
      }
      else
      {
         stamp
      }
   }
}