The two most commonly-used volume modes in iOS are the ringer volume and media volume. The ringer volume controls the volume of text tones, ring tones, and notification sounds, while the media volume controls the volume of your music and videos.
The only problem is, iOS likes to default to the ringer volume all the time, unless you have media playing. If you do, that's the only time the volume buttons will actually change the media volume level.
If you don't like that solution, then hold on to your seats, because we're going to be showing you a new free jailbreak tweak called SwitchHUD, which takes volume switching to the next level by letting you manually toggle between the two at any time with an Activator action.