lost channels

[Barbarafb]

I have a Sagem PVR 6200T. After updating and saving the "new channels" when prompted, three channels had disappeared - BBC1, BBC2 and NEWS24. I have never had this problem before having used Sagem's update so can't understand it. I have tried a new channel search, also swithced off and on again, but to no avail. It seems I may have to resort to running the manufacturer's default settings but am reluctant to try that until I hear from one of you wizards out there. I'd be immensely grateful for any help.