Texture python problem

obj = Blender.Object.Get('Arm')
mat = Material.Get('SHIRT_ROT')
#footex = Texture.Get('SHIRT_D')
#footex = Texture.Get('SHIRT_C')
footex = Texture.Get('SHIRT_E')
mat.setTexture(0, footex, Texture.TexCo['OBJECT'])

hi ! i got the following settings and when i change the textures they work good but one does not overtake the
[‘OBJECT’] settings. in blender they work fine. (i use SPE) when i save the scene again and have that one linked in blender the changes don´t effect the object anymore !?

anyone an idea why ?

for what does the index 0 stand? when i change him some settings change the texture and some not !?