PositionTexture, (3d programming sucks)

PositionTexture doesnt do anything on my computer. I press the arrow keys, the numbers change, but the texture doesnt.
My computer is less than a year old and I have the latest blitz update.

I have a radeon IGP 320 M, and I cant seem to get any updates.

; PositionTexture Example
; -----------------------

Graphics3D 640,480
SetBuffer BackBuffer()

camera=CreateCamera()

light=CreateLight()
RotateEntity light,90,0,0

cube=CreateCube()
PositionEntity cube,0,0,5

; Load texture
tex=LoadTexture( "media/b3dlogo.jpg" )

; Texture cube
EntityTexture cube,tex

; Set initial uv position values
u_position#=1
v_position#=1

While Not KeyDown( 1 )

	; Change uv position values depending on key pressed
	If KeyDown( 208 )=True Then u_position#=u_position#-0.01	
	If KeyDown( 200 )=True Then u_position#=u_position#+0.01	
	If KeyDown( 203 )=True Then v_position#=v_position#-0.01	
	If KeyDown( 205 )=True Then v_position#=v_position#+0.01	

	; Position texture
	PositionTexture tex,u_position#,v_position# 

	TurnEntity cube,0.1,0.1,0.1
	
	RenderWorld
	
	Text 0,0,"Use cursor keys to change uv position values"
	Text 0,20,"u_position#="+u_position#
	Text 0,40,"v_position#="+v_position#
	
	Flip

Wend

End