Audio output going out of balance

I normally leave my speaker output balanced right in the middle (under System Prefs>Sound>Output), however I have noticed that my audio output has been going out of balance by itself recently.

One speaker will sound louder than the other and sure enough, I'll go to the system prefs and the balance will be off. Nobody has else uses my machine and I know that I don't ever touch the audio output.

I have an iBook G4 running 10.4.11 connected to a pair of Brookstone speakers and subwoofer.

 

Nevermind. After searching the forums I found that this was a common bug with G4s that Apple never fixed. A mystery though!