Rear view camera 640d won't deploy properly

[Jimjimjeroo]

Hi,
Seen various posts about the rear view camera on here but none specifically detail my problem. The problem got worse over time and to start with disappeared when it rained. When going in to reverse the camera tries to deploy but does not get all the way out. It then 'resets' and goes back in to try again. This cycle repeats with the up shot being a view obscured by the bmw badge, then nothing, then an obscured view again as the cycle repeats. The camera can be grabbed and pulled all the way out by hand. I tried the simple fix of just spraying in wd40 through a gap. This seemed to work for 10 minutes or so. Today I have been fiddling about more and took the camera out to see if I could lubricate anything. I found that the camera deploys properly when not mounted through the boot lid, but not when mounted properly. Also that if I leave the black rubber waterproofing gater off when re-mounting it also works. This leads me to believe that the gater is somehow stopping the deployment. It all seems like a tight fit does anybody have/had a similar problem? and do you know if there is any adjustment? I notice a strange tapered pin that comes through one of the holes in the camera assembly that does not seem to hold anything in place and wondering if this is a 'gauge' for adjustment as at the minute when mounted the tip of the pin is not in the centre of the hole.