You have to set your sql instance port from dynamic to something static. If its the only instance on the server, than you can use the default port of 1433. If its not the only sql instance, than you may want to use something else, like 2433.
then your connector setting should go like this. notice the (:) after the port number!! very important!
jdbc:jtds:sqlserver://SERVER_NAME:PORT#:/INSTANCE_NAME;appName=DATABASE_NAME
heres mine
jdbc:jtds:sqlserver://server1:2433:/sqlexpress;appName=openfire
Hope this helps
Also, you may want to update the driver that is used for openfire. you can download it here.