Go into Avdap Mon and open it. This is on the voice mail itself. Watch the screen and preform a fax watch what the screen shows for the dialed number with the 92001 and with ARS which I am assuming is 92000. This should tell you what is being added and what is being deleted in the dial string. Providers are picky with PRI's they sometimes echo toll fields and other things. The Avdap Mon will tell you right awa if its a error with the programming or the provider.