On my 2004 NB Convertible I have a driver-side window problem: Normally, when opening the doors, the front windows drop slightly for the glass to pass under the seal grove in the top. When the doors close, the windows close up again automatically. My driver-side window appears not drop down and close back up automatically as the door opens and closes. It wedges towards the outside of the seal grove. Only opening the window slightly and closing it manually does the job. How could the problem be corrected ? Thank you for your suggestions and help.