Strange Locking Issue

Bought a mg zr 3 door 1.4 recently and for some strange reason if im inside the car and i lock the doors using the leaver on the door sill it locks all the doors but then if i lift it back.up nothing happens and im then trapped inside and have to put the window down and put the key in the door to get out! Also tried lifting the passenger door but get the same result does anyone know why this happens

Cheers Jamie

from the last news http://ift.tt/1yHJbOw

via IFTTT