I'd take a T6 driver, refer to the disassembly thread and put that plate back into place. It should slide into grooves and once that's done it really shouldn't shift (it certainly doesn't shift at all on either of my two 8700c's). However, that's me and I have taken apart several models. If you're worried about not getting everything together properly or messing something up then a warranty exchange is really your only other option.