Had my D700 for some months now so fairly well used to it. However, unless I'm missing something I think it has developed a problem. In aperture priority mode, the sub-command dial is intermittently refusing to alter the aperture. As I write, it has the new 50/1.4G fitted and it won't budge from f2.5; I turn it off, switch to my 35/2.0D and it sits at f32, refusing to move. I switched it to M mode, and the dial is still out on strike. Am I missing something somewhere, or is it a trip back to Nikon? Thanks.