Sky cube upside down

I have searched the manuals and the forums, no luck.

My problem is the sky cube appears to be upside down, but really its only the mountains;

code =

sky skycube =
{
type = "sky_free3_512+6.tga";
layer = 5;
flags = cube, visible;
}

It doesnt matter how I insert, tried script and WED project manager, same thing happens either way.

Any help is appreciated

Obviously I didnt search hard enough. Problem solved, just changed .tga to a .bmp for a temp fix