Occasionally, the volume on my 4S increases on its own, as if it thinks someone is pushing the volume up. At first I thought this was a case issue (even though I was using Apple's bumper case) but then, even with the case off, it was still happening. I took a video of it, in case I need to prove it to some genius in the future. It occurs inconsistently. Here is the link to the video. This makes using headphones impossible. It's also super annoying, trying to do something on the phone with that volume bar in the way. Searching for a solution hasn't given me any answers. Anyone else having this issue? Is a trip to the Apple store my only solution? Thank you!