Try this. In Profiles press the thumbwheel the select Show Tunes, highlight the tune and press the thumbwheel and select volume. This should allow you to change the volume.
Thanks, RCBJR. When you do that, there's a note at the bottom of the screen that says that the volume only affects the ring tone when you're sampling it...not when you've enabled it. Seems crazy. Are your enabled ring tones sufficiently loud?
I set my volume for ringtones to high and when I select them they are loud but when the phone rings they are all so low it's almost useless. I think there is a bug or something.
Try making a call and using the speaker phone. Turn the volume up on the speakerphone to 100% end the call and your ringer will be loud again. Another bug.