Thanks again for the update. A recording was scheduled for 18:00 today and it failed:-
Jul 7 17:59:30 Ubuntu tvheadend[2766]: dvr: "CSI: New York" on "5USA" recorder starting
Jul 7 17:59:30 Ubuntu tvheadend[2766]: dvr: unable to find access (owner '(null)', creator 'Auto recording by: 80.6.91.33')
Jul 7 17:59:37 Ubuntu tvheadend[2766]: mpegts: 698MHz in Freeview - add raw service
Jul 7 17:59:37 Ubuntu tvheadend[2766]: service: 3: 698MHz in Freeview si 0x27827f0 TurboSight TBS 62x1 DVBT/T2 frontend : DVB-T #0 weight 0 prio 10 error 0
Jul 7 17:59:37 Ubuntu tvheadend[2766]: service: 2: 698MHz in Freeview si 0x3626210 TurboSight TBS 62x1 DVBT/T2 frontend : DVB-T #0 weight 0 prio 10 error 0
Jul 7 17:59:37 Ubuntu tvheadend[2766]: mpegts: 698MHz in Freeview - tuning on TurboSight TBS 62x1 DVBT/T2 frontend : DVB-T #0
Jul 7 17:59:37 Ubuntu tvheadend[2766]: linuxdvb: TurboSight TBS 62x1 DVBT/T2 frontend : DVB-T #0 - starting 698MHz in Freeview
Jul 7 17:59:37 Ubuntu tvheadend[2766]: mpegts: 698MHz in Freeview - started
Jul 7 17:59:37 Ubuntu tvheadend[2766]: mpegts: 698MHz in Freeview - open PID 0012 (18) [20/0x2f7cd70]
Jul 7 17:59:37 Ubuntu tvheadend[2766]: eit: installed table handlers
Interestingly the DVR Autorecord entries also had owner as blank and Creator as an IP address. The one that had worked had Dave and Dave (the user I created for access restrictions in tvheadend).
When I selected to record the program that failed it started recording fine!
I have changed the recording entries to match owner and creator.