4S volume goes up by itself

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!

 

Do I need Apple care, cuz I don't. I got the 4S release day.

 

Thanks all. Took it in last night; got a new iPhone. The genius opened up the phone and tried to clear off some "junk" he said is probably causing the sticking. This caused it to became even more sensitive, so I got a new one.

While I was waiting for him to do that, I had the unfortunate idea of listening to the "iPad basics" class. Wow that guy said about 10 things wrong.

My favorite: "See, the email program is connected to your address book program! It knows that this email is from Mark, and it puts Mark's picture up next to his name." The only problem was that the email was from David. Mark was there because it allows you to "Mark" the mail as unread or flagged. Yikes. I choose to walk away.

 

That's because it momentarily goes to speakerphone.

 

Thanks all . . . the phone has been replaced at the Apple Store. It was a stuck button.