Sony TV sound problem

I have a Sony Bravia KDL32S2530 linked to a Pace Sky+ box(TDS47ONB) all of a sudden the sky + remote controller has stopped controlling the sound level on the TV, everything else works ok with the controller. I have an old sky standard remote so I tried that and it operated the sound level on the TV. So thinking the Sky+ controller was faulty I purchased a new one, and to my dismay I found the same problem. The sound level is controlable with the switch on top of the TV and also the Sony remote, and the old Sky standard remote. The Sky+ remote does everything it should except the sound level. Any ideas please ? Thanks in anticipation Pearson