• GrailsDaoImpl is a singleton bean but keeps the session and the boolean indicating if the session was pre-existing as class-scope fields. So users have seen that it's possible for a 2nd thread to overwrite and close the session before the 1st thread is finished
• although GrailsDaoImpl puts its session-related code in a try/finally, GrailsFilterInvocationDefinition does not, so it's possible to leak connections

I've fixed this in the version of the plugin that I sent to you but to help out the users who are affected by these bugs I posted fixed versions to the mailing list and am attaching them here until the plugin is updated.