Thanks for the reminder @terence7 – After opening your file, it looks correct to me:

So I’m wondering if you’ve been laying our your UV’s with a non-square texture loaded in the UV image editor. Whenever laying out UVs, you want to ensure that either no image is loaded in the image editor or that a perfectly square image is loaded (1024×1024 pixels for example). See when I load a rectangular image, the UVs stretch to fit:
