Ans Tamaki
I uderstand that the hdd is separate from the image and therefore any files will remain intact.However when I reflashed my duo on a previous occasion on a new bh image, the duo saw the hdd and I mounted it ok.It would record on timeshift and also instant record.When I tried to record using the timer it would go through the motions ,the a " recording has started " message would show and the timer menu would say recording the programme...........but no red recording light came up on the duo and no recording was made.To get the timer recordings to work I tried hard resets etc but to no avail. Inialised the hdd and all worked.I restored my personal backup this time on upgrade and all ok