I have recently experienced a problem with my D800 when the grip is attached. Inconsistently, the monitor will stop working followed by an inability to use the autofocus. I can still manually focus and still get a good shot but I can't preview the image nor can I access my menu functions. If I remove the grip the problems go away. Turning the body off then on again will allow me to get a couple more shots but then the problems continue soon afterwards. I went back to my retailer and tried a new grip and the problems still occurred. We put my grip on their demo D800 and there were no problems so elimination led me to believe this is an issue with the body. I searched the forum for a similar issue to no avail but I am hopeful someone will have some insight on this. I'm not looking forward to the rumored 6-8 week turnaround from nikon repair. Your insight is most welcome. Thanks.