Ejb timer persistence

Is it possibile to store ejb timers information in a JDBC persistent store instead of the default file store ? I know it can be done in a clustered environment, but what about a standalone WebLogic instance  ?
- I added <timer-descriptor>
                <persistent-store-logical-name>mystore</persistent-store-logical-name>
            </timer-descriptor>
to weblogic-ejb-jar.xml for my application
- in WLS console, I added a JDBC persistent store  named mystore, pointing to a specific data source

but deployment fails with the message "there is no persistent store with name 'mystore'

-- Peter