hi, for the old nissin di866 user, is that possible to upgrade nissin di866 firmware? cause when i pair the nissin di866 to nikon d7000 when the iso set to auto the camera iso only can go till iso400 although i set the auto iso to 6400. it seem like when pairing with nissin di866 the iso only can go higher till iso400, if i'm using in buillt camera flash the iso can go till 6400, i try to use in built camera when taking the photo indoor it state there it was using auto setting much higher iso but at the same ambient light when i change to nissin di866 it only record at iso400 although the setting is over iso 400, do you have a same problem?