I discovered a new undocumented feature for the first time last night - called up the program schedule and was horrified to see that only programs due to record in 6+ days were showing. All my earlier schedules had gone. Tried putting into standby and back on but no change, even tried adding new recordings. Had to rseort to pulling the power lead and full reboot to get the schedule to restore the display correctly.
Have had loads of the "lost recordings" fault but this is first time I've had lost schedules.