Video Skips Frame When Viewing Playback Of Motion Detect Video Only

I have a Night Owl NVR that is constantly doing this. It does it to the point that any video I need - it's just a lost cause. I've called tech support - who made me format it - wiped it clean and started over and the problem hasn't gotten any better. The firmware is up to date (always has been). Does anyone know about the Night Owl NVRs or can suggest what to do ? Thanks !