[G4] sound issue on G4 cube

[Barry Stennett]

I've stumbled into an unusual issue with my cube....

At random times, the speaker icon will pop open and the sound volume 
will sometimes (but not every time) change - usually to a very low 
volume setting from it's typically high setting.

If itunes is active when this happens, itunes will pause whatever it is 
playing and I have to tell it to start again. In addition, whatever 
program is activating the speaker control also demands a huge amount of 
processor power for less than a second, then simply goes away.

Any ideas or suggestions?

Thanks.

Barry