Why are the scrolling textures on a linrenderer bright green?

Updated and bounty added. See recent comments and updated answer below.

I am using a line renderer with a transparent texture on it. The texture has a uv scroll to move it constantly left to right thustly:

var offset = Time.time * scrollSpeed;
renderer.material.mainTextureOffset = Vector2 (-offset%1,1);

I'm using the iphone/transparent/vertex color shader which works fine on everything else but on this sucker.

The textures are psd's, created over a transparent background in pshop.

Please help, this is driving me knuts!

Turns out that switching the shader used from: iphone/transparen/vertex color, to: transparent/vertex lit took care of it. Don't know why though.

***Opened the question back up. If I use a shader that doesn't need lights the texture will always be yellow or green. I don't want to incur the cost of unneeded lights. Anyone got an answer for this long overdue question?