LG PM-225

I just purchased this phone and was going through putting all the settings the way I like them when I discovered a small problem. I like to set my voicemail and messaging notification to vibrate. I don't like the beeps or sounds, I just want the phone to vibrate. I've had that on every phone I've had in the past. This phone has that option, but I have it selected and it still beeps everytime I get a voicemail or text message. Does anyone have any ideas?