Recording service suddenly failed

[Bobins]

Recording service has suddenly stopped recording. Anyone any ideas what might cause this error:-

2009-09-12 14:17:00.349 VERBOSE [5] pending: (1583) Star Trek: Enterprise 24/09/2009 14:00
2009-09-12 14:17:00.349 VERBOSE [5] - checking Without a Trace
2009-09-12 14:17:00.349 VERBOSE [5] pending: (1587) Without a Trace 24/09/2009 22:00
2009-09-12 14:17:00.349 VERBOSE [5] - checking Without a Trace
2009-09-12 14:17:00.349 VERBOSE [5] pending: (1588) Without a Trace 24/09/2009 22:55
2009-09-12 14:17:00.365 WARNING [5] Unexpected error logging recording schedule: System.NullReferenceException: Object reference not set to an instance of an object.
at GBPVR.RecordingService.x93f60a55016d55c4.xcba1f05fb5a46d5f()
2009-09-12 14:17:15.894 VERBOSE [14] RecordingFactory.loadScheduleRecordingByOID()
.......
2009-09-12 14:17:15.894 VERBOSE [14] getValue cached value: /settings/AutoConvertTSToFormat : No Conversion
2009-09-12 14:36:15.872 VERBOSE [14] Conversion thread configured for ASAP
2009-09-12 15:07:15.783 VERBOSE [14] Conversion thread configured for ASAP
2009-09-12 15:38:15.695 VERBOSE [14] Conversion thread configured for ASAP
2009-09-12 16:09:15.606 VERBOSE [14] Conversion thread configured for ASAP
2009-09-12 16:40:15.518 VERBOSE [14] Conversion thread configured for ASAP
2009-09-12 17:11:15.429 VERBOSE [14] Conversion thread configured for ASAP
2009-09-12 17:42:15.341 VERBOSE [14] Conversion thread configured for ASAP
2009-09-12 18:13:15.252 VERBOSE [14] Conversion thread configured for ASAP
2009-09-12 18:44:15.163 VERBOSE [14] Conversion thread configured for ASAP
2009-09-12 19:15:15.127 VERBOSE [14] Conversion thread configured for ASAP
2009-09-12 19:20:00.265 ERROR [5] Caught unexpected exception: System.NullReferenceException: Object reference not set to an instance of an object.
at GBPVR.RecordingService.x93f60a55016d55c4.xcba1f05fb5a46d5f()
2009-09-12 19:20:00.466 ERROR [5] Caught unexpected exception: System.NullReferenceException: Object reference not set to an instance of an object.
at GBPVR.RecordingService.x93f60a55016d55c4.xcba1f05fb5a46d5f()
2009-09-12 19:20:00.667 ERROR [5] Caught unexpected exception: System.NullReferenceException: Object reference not set to an instance of an object.
at GBPVR.RecordingService.x93f60a55016d55c4.xcba1f05fb5a46d5f()
2009-09-12 19:20:00.868 ERROR [5] Caught unexpected exception: System.NullReferenceException: Object reference not set to an instance of an object.
at GBPVR.RecordingService.x93f60a55016d55c4.xcba1f05fb5a46d5f()
2009-09-12 19:20:01.069 ERROR [5] Caught unexpected exception: System.NullReferenceException: Object reference not set to an instance of an object.
etc ad infinitum until recording service restarted.