How can I avoid this camera tracking error? "Some data failed to reconstruct (see console for details)" I'm currently following Sebastien Konig's Match Track Blend DVD and have encountered a problem where despite matching camera type, lens type and trying to solve for distortion, I'm getting the following console messages when I try to Solve Camera Motion:

bpy.ops.clip.solve_camera()
Some data failed to reconstruct (see console for details)


And I'm getting an average Solve Error of 0.9561, where I'm used to getting .4 and below. So what's going on?

The related files can be found here.

This may be related to another question I've asked on the site - Why can I not select camera trackers in the graph view of the Movie Clip Editor?
I figured that the issues were different enough that I should give them different questions.

Many thanks to everyone who built and everyone who visits this site. StackExchange/Answers style-sites are very useful to me and I appreciate any time spent trying to answer the questions people ask here. (Thus ends that digression!)
Simple:
Here are a few measures to fix this issue:
Take good footage that isn't to shaky or blurred.
Double check that all of your tracks are accurate.
Add more accurate tracks.
Delete a track, then solve camera motion if it didn't help, chose a different track and then and repeat.
make sure that not all your tracks are on one single plane in space (eg. on a wall)
If all fails, then your shot is simply to difficult to solve.