The point of this update is to fix an important security problem that would let a logged-on user with QueueMetrics call-listen privileges to access unauthorized files if your servlet container is running as "root".
If you keep audio recordings, we strongly suggest upgrading in any case, even if you have stricter security in place (e.g. running QM under Java Security).
The other important change in this release is a new logging architecture that will keep track of QueueMetrics users logging on and off. You will notice that when you run QM for the first time, it will complain that the database has to be upgraded and will perform the upgrade - don't worry, this is normal.
A number of other bug fixes and minor changes have been performed as well.