[Dabhand16]

Nice to hear from you again Woody - was only thinking the other day that we had not heard from you for a while.

Sorry it seems that there is no obvious answer to the problem, but it might be worth a call to Nikon to see if they can suggest anything, as VinnyP said, it might be they can tighten it for you, but it might then gradually do the same again.

Perhaps a bit of gaffer tape lightly tacked across the zoom ring would hold it in position?