in Blender 2.76b, I tried to track a video, and I got an average solve error of 0.2963.
the video was of 300 frames png sequence and there were eight tracker points…
the problem I faced was that though in movie clip editor, the tracker points were tracked upto the end of the video,
in 3d window, while looking through the camera, the empties/set up scene/soild/floor etc all were obeying the tracker upto around frame 230 and the tracker points remain still there after
Another thing to check… Do you have enough trackers in the shot after f244? You need to have a minimum of 8 (from memory) visible at all times for the solve to work, so maybe you need some extra ones on the last section. Other than that I’m out of ideas, sorry :o
Agreed, you need a lot more trackers. 8 is the minimum, but the more you have, the better the track will be. Looking at those screenshots, there’s hundreds of places you could track easily.