I did the same as one of the posters above.
1. Take battery cover off
2. Find a thick piece of paper, look for something dark in color (advertisements etc are normally done on thicker paper).
3. Cut a 1/4"x1/4" piece and slip it in between the volume rocker and phone, I'd suggest putting the paper in the middle so it doesnt bias the feel of the rocker button to one side or another.
4. Bend the piece of paper back a bit and trim so you have a little lip left for removal purposes.
5. Put Battery cover back on and make sure that the paper is not visible.
Problem solved.