Android Cyanogen Trebuchet launcher

I'm trying to modify launcher.db file in trebuchet configuration (/data/data/com.cyanogenmod.trebuchet/databases/launcher.db) in my app. But when I ask to trebuchet to reload it is always broken and I have to get back to original configuration.

I've root access and I changed the access right on the files. I can read the list of the apps. I'm not sure if the issu is on the reloading or at the oppening of the file.

If any one has an idea?