UV unwrapping problem

Hi! Well, I’m fighting with UV’s these days and finally I’ve got this funny unwrapping…As you can see, it’s a very simple model, for learning, but, being made with quads around the seam, in the UV editor some appear as triangles, does anyone know why?

Thank you!

Remove any doubles and then recalculate face normal (Ctrl+N)

Face normals, that was the thing. Thanks!