Whenever I render a single frame of my animation, for all key frames except one it will just give me black real quick while that odd one out will show me an older render of mine from that same keyframe. I could switch cameras, change the position of anything in the scene, or alter rendering settings but it will just give me back the inital 720p render without even looking like it rendered anything at all.
When border is enabled in the rendering, I get an error message saying "Border rendering is not supported by sequencer."