Stereo keeps changing volume randomly autonomously?

So the stereo system in my 2008 Tribeca has started to get a mind of its 
own. For some reason, the volume goes up or down on its own, without you 
touching the controls. You can see the volume level changing on its 
digital display, it'll hunt around from 0 to 30 or anywhere in between, 
except where you last left it. When this happens, you can still manually 
adjust the volume with either the volume knob on the console or on the 
remote volume control on the steering wheel, but it won't stay there for 
long. Problem started a couple of days ago, and it seems to start 
happening maybe after 5 minutes after starting the car. What could 
possibly be causing this problem?

On a possibly related note, the car's battery has had some corrosion on 
it, possibly some cells have gone bad. Could this have anything to do 
with it? Just throwing that out there as a random observation, I'm not 
saying that this is the cause, just asking.

	Yousuf Khan