Edges "twisted" by the subsurf modifier I am learning modeling on Blender and I have some difficulties with the subsurf modifier. 

Here is my mesh with the modifier display off :


And here it is with the display on :


Some edges are twisted and I don't understand why. 
I tried to :


removes doubles
recalc normals
delete the vertices and make a new one (makes it even worst)


Could someone, please, explain me why it is happening and how can I correct it?

Thank you,
It looks to me like there are vertices in your mesh that are not attached.  See the video below.



Double check all of the vertices around your twisted area and merge those that aren't connected by press Alt+M on the keyboard.