Comment 2 for bug 295292

Andrew, your bug report is really detailed, thanks.

I don't know how to solve the problem. However, as a temporary fix you can use wacomcpl, copy the .xinitrc created to another name (for example "calibration"), make it executable and create a panel launcher with, as command:
sh /path/to/the/file/calibration

Then click on the launcher each time the calibration is off.

Try also posting in linuxwacom-discuss since your troubleshooting is already quite thorough, they may get it fixed faster (but they might ask you to install 0.8.1.6 version first, see https://help.ubuntu.com/community/Wacom/LatestDriver ).