Texture warping in S4S?

I wonder if someone can help me out.

I'm trying to make a new sign mesh, It's my first time using blender so i'm having some trouble,

So far it looks great in blender but when I import it to S4S it has texture warping like its been streched, but only on the back of the sign.

I followed a tutorial on youtube, So I don't know what's going on.

I re uv mapped it once incase i accidently moved or resized the mesh after uv mapping it the first time,

I also made sure there was only one uv map called uv_0

Hope someone can help me fix my mesh.

Any suggestions will be helpful.

Thanks in advance.