Yep - that seemed to do the trick, almost as soon as I put the new xidle binary in place.
2015-02-18 16:14:12: Auto Configuration: Set Restart Stalled Slave value to ‘False’
2015-02-18 16:14:12: Launcher Scheduling - Error querying idle time: /mount/apps/linux/thinkbox/deadline/Deadline7/bin/xidlewrapper: 5: exec: ./xidle: not found
2015-02-18 16:15:12: Launcher Scheduling - Launching slave anson because this machine has been idle longer than 2 minutes (scheduling group “idle-test”)
2015-02-18 16:15:12: Launching Slave: anson
2015-02-18 16:19:13: Auto Configuration: Set License Server to ‘@delany’
2015-02-18 16:19:13: Auto Configuration: Set Restart Stalled Slave value to ‘False’
2015-02-18 16:23:14: Launcher Scheduling - Stopping slave anson because this machine is no longer idle (scheduling group “idle-test”)
2015-02-18 16:23:14: Sending command to slave: StopSlave
2015-02-18 16:23:14: Got reply: anson: Sent “StopSlave” command. Result: "Connection Accepted.
2015-02-18 16:23:14: "
2015-02-18 16:24:16: Auto Configuration: Set License Server to ‘@delany’
2015-02-18 16:24:16: Auto Configuration: Set Restart Stalled Slave value to ‘False’
2015-02-18 16:26:16: Launcher Scheduling - Launching slave anson because this machine has been idle longer than 2 minutes (scheduling group “idle-test”)
2015-02-18 16:26:16: Launching Slave: anson
Thanks Ryan.