This report will find all agents running a version OTHER than the one that is currently loaded in your KBOX.

SELECT NAME, IP, CLIENT_VERSION FROM MACHINE
WHERE
MACHINE.CLIENT_VERSION != (SELECT VERSION FROM CLIENT_DISTRIBUTION WHERE ID = 1)

*Note the WHERE ID = 1 part limits it to windows client.

Though currently all version numbers are the same if they were to ever change between OS's you would change this.