Here is a quick fix. Just uninstall the tuning-plugin for diablo and reinstall the one for tuning-plugin for chinook. It should work.
Here are the steps.
(1) Go to Application Manager and uninstall Canola2-tuning-plugin.
(2) Go to Application Catalog and edit Maemo Extras, and put Chinook for distribution.
(3) update and reinstall Canola2-tuning-plugin.
Now it should work.
Don't forget to change the distribution back to whatever you have before. But don't update the tuning-plugin after that until they fix the one for diablo.