I just noticed this now, but in this image (http://img180.exs.cx/img180/2452/untitled39wr.jpg), the gate that is there, it is a sprite isn't it? Because if you look closely at the picture, you can see the top edges transparency isn't perfect because you can see a line going across the width of the gate. Not a major major thing as I don't think it would be noticeable with the noise on, but you never know.

Regards,
Ayrus