Help with collisions

Hi. I hope help me with a trouble of collisions. Here my code:

Graphics3D 640,480,16,1

SetBuffer BackBuffer()

Const FPS=60

global rayo,platillo,enem,metal,secuencia

x_flot1=0
y_flot1=-0.25

camara=CreateCamera()
CameraRange camara,0.05,10

luz=CreateLight()

platillo=LoadAnimMesh("platillo.b3d")
ScaleEntity platillo,0.04,0.08,0.08
RotateEntity platillo,0,90,0
PositionEntity platillo,0,-0.2,0.5
ExtractAnimSeq(platillo,0,40);Secuencia 1
ExtractAnimSeq(platillo,40,60);Secuencia 2
secuencia=1
animate platillo,1,1,secuencia,0

rayo=loadsprite("rayo.bmp")
hideentity rayo

enem=loadmesh("enemigo.b3d")
hideentity enem

metal=loadtexture("metal.bmp")

If KeyHit(32) Then   
   crea_disparo()
   SoundVolume sonido_laser,0.5
   PlaySound sonido_laser
endif 

Type disparo
   Field tipo
   Field vel#
End Type

Function crea_disparo()
   ray.disparo=New disparo
   ray\tipo=CopyEntity(rayo)
   ScaleSprite ray\tipo,0.02,0.02
   EntityType ray\tipo,1
   EntityRadius ray\tipo,0.02

   If secuencia=1 Then
      PositionEntity ray\tipo,EntityX(platillo)+0.05,EntityY(platillo)+0.015,EntityZ(platillo)
      ray\vel=0.05
   ElseIf secuencia=2 Then
     PositionEntity ray\tipo,EntityX(platillo)-0.05,EntityY(platillo)+0.015,EntityZ(platillo)
      ray\vel=-0.05
   EndIf
End Function 

Function mueve_destruye_disparo()
   For ray.disparo=Each disparo
       MoveEntity ray\tipo,ray\vel,0,0
       If EntityX(ray\tipo)>EntityX(platillo)+1 Or EntityX(ray\tipo)<EntityX(platillo)-1 Then
          FreeEntity ray\tipo
          Delete ray
       EndIf
   Next
End Function

Function destruye_disparo()
For ray.disparo=Each disparo
    If EntityCollided(ray\tipo,3) Then
       FreeEntity ray\tipo
       Delete ray
    EndIf
Next
end function 

Type flotilla1
   Field tipo
   Field vel#
End Type

Function crea_flotilla1()
 For i=1 To 5
       flot1.flotilla1=New flotilla1
       x_flot1=Rnd(1,2)*p_flot1
       flot1\tipo=CopyEntity(enem)
       ScaleEntity flot1\tipo,0.08,0.08,0.08
       PositionEntity flot1\tipo,x_flot1,y_flot1,0.5
       EntityTexture flot1\tipo,metal,0,1
       NameEntity flot1\tipo,i
       EntityType flot1\tipo,3
       EntityBox flot1\tipo,-0.04,-0.04,-0.04,0.08,0.08,0.08
       y_flot1=y_flot1+0.1
       flot1\vel=0.01*v_flot1
       v_flot1=v_flot1*-1
       p_flot1=p_flot1*-1
   Next
End Function 

crea_flotilla1()

Function repos_flotilla1()
   For flot1.flotilla1=Each flotilla1       
       If EntityX(flot1\tipo)>0.6 Or EntityCollided(flot1\tipo,1) Then
          If EntityName(flot1\tipo)=1 Then
             PositionEntity flot1\tipo,Rnd(-1.3,-0.6),-0.25,0.5
          EndIf
          If EntityName(flot1\tipo)=3 Then
             PositionEntity flot1\tipo,Rnd(-1.3,-0.6),0,0.5
          EndIf
          If EntityName(flot1\tipo)=5 Then
             PositionEntity flot1\tipo,Rnd(-1.3,-0.6),0.25,0.5
          EndIf
        EndIf 

       If EntityX(flot1\tipo)<-0.6 Or EntityCollided(flot1\tipo,1) Then
          If EntityName(flot1\tipo)=2 Then 
             PositionEntity flot1\tipo,Rnd(1.3,0.6),-0.125,0.5
          EndIf
          If EntityName(flot1\tipo)=4 Then
             PositionEntity flot1\tipo,Rnd(1.3,0.6),0.125,0.5
          EndIf
        EndIf
Next
End Function 

Function mueve_flotilla1()
   For flot1.flotilla1=Each flotilla1
       MoveEntity flot1\tipo,flot1\vel,0,0
   Next
End Function

period=1000/FPS
time=MilliSecs()-period

Collisions 1,3,3,1

While Not KeyHit(1)

       Repeat
	elapsed=MilliSecs()-time
       Until elapsed
       ticks=elapsed/period	
       tween#=Float(elapsed Mod period)/Float(period)

	For k=1 To ticks
	    repos_flotilla1()
            If k=ticks Then CaptureWorld
            time=time+period
            mueve_flotilla1()
            mueve_destruye_disparo()
            destruye_disparo()
            updateworld
        next

   RenderWorld tween

   Flip

wend
End

the first time (before return to start position) , all work fine:

http://img129.imageshack.us/img129/9248/img1kb5.th.jpg

after return to start position, laser collides with enemy, but enemy is in another side :-(

http://img353.imageshack.us/img353/4147/img2jf1.th.jpg

What´s wrong. :-(

Thank you very much to help me. :-)