Well it looks like your signal levels are fine, although some sats are lower in strength than i would have expected with a 1M dish - perhaps the dish has moved a little with bad weather? I doubt a new channel list will sort your problem as a full re-scan should bring back any channels which have moved or been replaced.
Just out of interest, did you switch the receiver off at the wall while you were away? It is possible that there is a power supply fault which can cause this sort of issue (i have had the exact problem with 2 Fortec Star receivers i own). The capacitors dry out with heat and time and when the receiver is off and cold, they cease to function - a quick test (if you don't mind taking the top off) is to heat the PSU area with a hairdryer for 2 or 3 minutes (WITH THE MAINS DISCONNECTED for safety), then plug in and give it another try. If that sorts your problem then you will need to get the box repaired.