You should have an option in the profile setting for that contact for Play sound IN HOLSTER, OUT OF HOLSTER, ACTIVE PROFILE, OR ALWAYS. You most likely selected ALWAYS, which plays that ringtone ALWAYS (obviously). Select ACTIVE PROFILE to only use this ringtone in your NORMAL profile. This way when you select the VIBRATE profile this person should only VIBRATE when they call, just like everyone else. GOOD LUCK!
06-05-10 09:45 AM