I was cleaning my buttons as they were sticky but im sure that was the actual cause of this.
Stuck or shorted volume down button. If it were a remote control (tv) with a soda spill causing it to stick or water shorting out the contacts, I would say to remove the battery, disassemble the keys and spray it down with a good electronics contact/component spray, let it dry out and put it all back together and you would be good to go.
I don't know if I would risk taking apart the n10 myself. If you did, be careful with the spray on plastic... A mild cleaner/alcohol which may damage the plastic. If you were cleaning it with water, you may get lucky and it could dry out on its own in a few days... If you have an air compressor or even 'a can of air', you could try that to dislodge whatever is making the button sticky or even moisture. (use canned air cautiously since it can create more moisture if over used... Just quick sprays around the button).
Last, I don't think Samsung would have an issue with rooting it... It's not a software issue and I also don't think cleaning out the button would be covered under the manufacturer warranty. Something you might have to pay the bill on.
