There are a couple of possible reasons why this happening and a couple of things to try to remedy it. First uncheck "Wrap UV" for both the U and V. When Wrap UV is engaged, the program tries to connect the vertex dots like a connect-the-dots drawing. As another option (or in conjunction with enabling the unwrap) try engaging the "Framed" option in your box layout and see if that will work for you. You will need to adjust your T-maps accordingly since everything will reposition slightly. I typically use Framed for everything I UV map because it makes the mesh easier to handle since vertexes don't bump up against the edge of the map area. Mark