I'm still a bit baffled as to why you won't just call Nikon and see what they say. Or better yet take it to where you purchased it. At the very least they will usually offer to cover the shipping back to Nikon for repair. I'll bet you Nikon will repair under warranty no questions asked. Forget about all the Internet naysayers and go for it!
Well, because I did contact them, mate... That was the first thing I did after putting the grip back in its original packaging.
And even after sending them pictures they won't go beyond "we can't yet tell you what it's gonna cost or if it's covered by the warranty, so send it to us first and we'll charge you for the shipping".
So, since this is not my first experience with Nikon, and they systematically have been bad, I'm building a case.
And of course it will be shipped via the shop which sold it to me... they are legally responsible for that as long as the mandatory 2 year warranty is in play, in the EU.