I'd like some advice. After purchasing a H4D-50 in November and having three "Communication Error" messages without a code, I sent it back and received a replacement. The replacement has been worse and no one at Hasselblad has been able to troubleshoot this. In addition to the general Communication Error, I've had numerous errors that read "Exposure Not Possible - Check Magazine." I checked the pins on the back and everything was fine. In every case, after I unplug the battery grip and plug it back in, the camera works fine. The camera works fine in every other regard. I get an error message typically once or twice a week and it's not really bothersome. But it is a problem (I don't think there's a magnetic field around my house that causes camera errors) and I'd like to resolve it. Does anyone have any experience with this? I'd like your help. At this point I'm probably going to ask for another replacement. I don't know what else to do.