As i said above mate; its common for the micro switches to pack up. basically you have 3 micro switches in each door to make sure the window drops correctly

1st - on the interior door handle
2nd - on the exterior door handle
3rd - in the door locking mechanism (this one keeps the window down once the door is left open)

The 3rd one is the most difficult to change, so if you ever get it go again, give me a shout if you need any pointers, i'm somewhat of an expert on them now!