Over the last 6 -8 weeks we have repeatedly lost channels currently have no channel 10, 12,15,16,17,18,21,22,23,24,26,27,28, etc. We have tried the Digital autotuning from the Menu button. It runs through but does not re find the channels that have disappeared. Other channels regularly pixelate and fail to display properly on screen when chosen. The ariel and cables were new last summer and everything worked fine initially. We have a Sony KDL-26EX302. Any suggestions ?