ActionScript 3.0 :: Swapping Tiles From Board (9 Frames)

I create a board using the class Baldosa (which is a tile on my .fla file with 9frames, each is a tile of a different color). I first create and array of numbers which indicates which frame (color) the baldosa element will display. As grey baldosas are more than the other colors (this is intended), then I unsort the array to avoid grey baldosas accumulating on the right side of the board. Then I push each baldosa in an array, and add each of them as child of the contenedorBaldosas(container) to avoid adding events for each Baldosa.

The problem comes when I want to check collisions. If there's a collision, I swap positions of each Baldosa. It only works if I swap the tile at depth number 0 and the last at depth 79, for the rest of Baldosas, it doesn't detect any collision (the baldosa clicked will return to its original position as nothing had happened. I made a trace and it seems the baldosa clicked doesnt collide with another baldosa in the array (each baldosa is given the name baldosaxx using the variable in the for loop), but rather an unnamed instancexxxx.

Also I'm treating the baldosa elements as Sprites, but as the baldosa in my .fla is a MovieClip, and it contains a Timeline where each frame is a baldosa of a different color, the problem may be also here.
package {
import flash.display.*;
import flash.geom.*;
import flash.events.*;
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