Problem solved. On the net I discovered that someone with the same fault was told that by pressing buttons in a certain sequence and inputing a code number the fault would be cured. They were unsuccessful because they were told the code no was on the remote, and as it wasn't ended up believing their remote was not genuine. The code actually can be found in the Sky handbook and varies according to the make of the TV. The handbook says how to remedy remote faults (although not specifically referring to volumn/mute) and when I followed their instructions (at the 3rd attempt as their instrucions are not very clear) I succeeded and my defective remote now works perfectly
garwen, December 2009
