Speaker Trouble

Hi
I have recently discovered a fairly annoying issue with my eMac 1GHz which I acquired last November.
Every so often I have to go into System Preferences to set the speakers on level balance, because they seem to adjust themselves automatically.
Like just a second ago I had to level them, because it was set far too much to the right

Anyone else had a similar problem or have a way around this?

have any of your other system preferences gone wacky lately?

yeah this happends on my ibook it is real weird it just will change when i plug the earplugs in or when just when it wants to. But IT is not so much of a issue because it is the schools