Aligning Textures in simple planes

Hi

I have a small and naive problem. I am creating a 2D tower defense game. My method is working with simple textured planes for all the graphics. The camera is fixed from the Y axis.
This is working well so far, but now I stumbled upon a problem. My towers have a base, which is static, and a head, which revolves to follow the enemies. To implement this, I use 2 planes fixed one above the other. The tower base is the parent of the tower head. Both of them have 128x128 textures, and both of them have the same scale (0.3x0.3).
When I instantiate a tower, there seems to be an alignment shift of the textures, and each tower looks a bit differently:

alt text

It seems that my assumptions are a bit naive. What am I doing wrong?

Thanks

Mike

From you screenshot it looks like it could be an effect of perspective. Go for an orthographic camera instead of the default perspective one...

By the way, how do you instantiate the tower? Does the head is instantiated with an offset value ? If parented to the base, it shouldn't, and have to be placed at 0,0,0 relatively to the base.