okay, I've searched the forum and found nothing to solve this problem...
i made a simple polycube and looked at the UV Map Editor. then i started beveling the edges(2 lines), the maps in the editor splitted and i can't sew them. when i select all the edges in the editor, found out that the edges in the beveled parts aren't selected.
with this problem, i don't think i can UV map, any hints on my problem?
once you alter the topology of a mesh i.e spliting or extruding then you will have to remap the mesh, so the answer to your question is you have to re-planar map the cube and the new UV map will include your bevel you can then move and sew to your hearts content