Driver side window,dropping

[R56]

Have been having probs with the drivers side window,it has dropped down about 2 to 3 mm at the B post end of the glass,and causes one hell of a wind noise when moving at speed,plus I am worried about water ingress,anyone have ideas about how to fix it.

[mini-ture]

I have the exact same problem! I did get someone to push it up whilst the window was being closed, this worked for a week or so then dropped again!