Its a dahua hdw ipc 4431C-A that i run the substream to a less powerful secondary BI system. It doesnt even have the option to select 1.3mp in the substream options only cif and d1. But every couple weeks it just switches from d1 to 1.3mp. Actually this cameras main streams fps goes from 12 to 20fps at the same time i believe. Accessing the web interface and resaving the video settings again fixes it. Anyone else ever experience this?