A problem with wire extension in soc encounter and seultra

I had a problem with pins' connection.In my design, I only want the wire to connect to the edge of the cell, not want one-half of their width extension at pins. 

In the layout, I drew square pins on M1/M2 pin layers, and generated cover blockage for the cell. Then I added this statement "NOWIREEXTENSIONATPIN ON ;"  to the lef file (after manufacturing grid statement), then in the encounter, when I finished SRoute, and did NanoRoute, there were still one-half of M2 width extension to the internal of the cell.
    

Then, I found in the ultra router reference, it said that: it support no wire extension rule at pins, so I tried to do place and route using seultra -m =250 and WRoute, but the routing result was nearly the same: the wire extended to cover the whole pins.

How can I solve this problem?

Thank you very much in advance!

Renee