128H x 256W map?

[salt サルト]

So, this PA belt require color map of 128H x 256W
I asked here and they told to put the UV to half side of the square, like this?
http://i61.tinypic.com/4loqo8.png
And then, I did a quick test on this:
http://i58.tinypic.com/2cft64o.png
the map is squeeze when i import it to dota 2 / blender.
any solution? or am i doing it wrong?

[HellJumper]

In the UV window, click new, enter in 1024 x 512 (this is 4x the size of your final texture size), then unwrap your model. You used to be able to unwrap to half the square, but that no longer works.