I have a Samsung Tocco snd it's great, but I'm having a problem with the volume on the videos. I have downloaded converted and downloaded a movie onto the phone and it plays perfectly but I can't change the volume -which is set at 0. I can see the volume controls for it but can't change it no matter what i try pressing or touching. It doesnt appear to be in the phone settings or even in the trouble shooting section of the guide. help!