I have a system with PTZ SD49425XB, 4MP HDW2431TM and 8MP HDW2831TM cameras using a NVR5216-16P-I NVR. For some reason, the 8MP cameras will only display in the main stream if set to lower than 8MP resolution. The camera is definitely connecting to the NVR and ethernet connection icon is displayed on the black screen. The sub stream does display video even when the main stream is set to 8MP (I believe the 16ch view uses the sub stream). The SD49425XB and HDW2431TM cameras work perfectly. I'm only using 6 out of the 16 channels right now and there's a ton of bandwidth left on the NVR (the NVR has 320Mbps capacity). The cameras work fine on other NVRs, so it doesn't appear to be an issue with the cameras. Could this be an issue with settings?