This looks to me that you applied an Unwrap UV modifier and then you did some modifications on the mesh.
Only apply an Unwrap UV modifier when you absolutly sure that the mesh is done and ready for unwrap. Otherwise, it results in bad surprises :)
What I suggest you is: In the UV-unwrap modifier, go to poly mode and relaxe the mesh by polygon - don't forgert to set the mark on the white box, which makes you select all seamed polys which corresponds to the selected one.