Same issue here with beta 11. After the first time it happened I thought I had some bad sectors as i had some recent crashes. After fsck'ing same problem. Checking permissions in .canola did not reveal any issues. I fixed it by renaming the canola.db file and allowing canola to create a new one (first startup hung, killing restarting canola made it happy after removing the db file). It worked again for about a week and then had the same error. Removing the db file fixes it for me but obviously you loose all our podcast settings, etc. Love canola, hope this can be squashed soon.
1242265366.8972 DEBUG system:112:_update_battery() Setting battery status to (1, 1.000000). 1242265366.9083 DEBUG system:224:_do_disable() Asking system to keep the screen light on. 1242265366.9245 DBG_W controller:433:db_locked() received DB locked signal but already notifying user, ignoring it ... 1242265368.2218 DEBUG controller:132:get_controller_for_model() looking for controller for model with filter 'Model/Notify/Error/Fatal' ...