Could be not enough bandwidth? For example, the max bandwidth setting may be too low or the network connection the video is being sent over is insufficient? My rationale is that when an image 'breaks up' in the middle of the day, generally it's not an imaging issue but a compression / bandwidth one.
@bickford I notice, looking at your config screenshot, you had the quality setting set to 6, for best. Try lowering to its default of 4. In our testing, increasing quality settings generally does not make a visible improvement but can significantly increase bandwidth consumption.