problems with my dvr

Over the last month we have noticed:

1) that we can no longer see the Weather Channel, either at 25 or 1025, it says it is "temporarily of air", but it never comes on any more.

2) when we try to do a title search through the guide, it will let us enter the 1st letter of a show and then it says" Listings currently unavailable"

we have rebooted it, bu tno luck, very frustrating!  Any ideas?