In addition there's a dirty workaround - write a script, which will click appropriate buttons to set that things. For example:
click("menu")
click("left")
click("down")
click("right")
click("set")
On sx130is above code will cause entering to the menu, navigate to the settings -> mute on/off; so it'll mute/unmute the camera
Dirty and not portable, but works. Just like a macro in Execel or something.
PS. It is good idea to add a little delay between clicks - to allow camera to follow your clicks;)
