When using IP cameras. The RTSP stream often runs from about halfway through the image on down. It is hard to explain, so I've attached a screenshot. If you look at the bottom of the image, you'll see what I mean. This ends up registering as motion, and it is recorded this way. So, it is not just a viewing problem. It is always on the lower half of the image, and lasts a few seconds. I've only used two IP camera models so far, Vivotek IP8332 and a Dahua model. Both are 1.3 MP. The FPS on the on-camera settings is between 10-15. The resolutions are 1280x720.
This happens on two different machines. The one that this screenshot is from is a beefy hot-swap raid server with 16GB of RAM. This happens despite there only being 4 cameras on it currently.