I have one DH4631C attached to a Dahua NVR 4104 ... that stutters. The clock will march along, and then - skip 2-3 seconds during daylight ...perhaps 10-12 seconds after dark is the norm. Bugs look like shooting stars leaving a tail on screen. I set the bit rate to 25 (the max). I am not sure of where to look next? Any thoughts would be appreciated. Thanks. Jim