Voicemail not Picking up

I installed FreePBX 2.1.3 and everything is working fine for the most part, except for the Voice mail. When my call hit what is supposed to be the voicemail box there is a click and then the call is disconnected. This happens on zap trunks as well as from extension to extension. The voicemail module is instelled and there are greetings in the mail boxes. Any help would be greatly appriciated.