We have a standalone NuPoint Voicemail system and three 3300 PBX's. Users on one PBX only are complaining of delays (sometimes in weeks) of their messages. It looks like the MWI doesn't always come on, an when it does, there is often the message that turned it on, and 2-3 much older messages they never heard.
I've done a bunch of searching, and the two suggestions I've come up with are to schedule a daily MWI refresh, or to switch to DTMF. I've scheduled the refresh, which is an improvement, but not seeing a voicemail for most of a day could still be a problem.
For the life of me, I just can't get DTMF to turn a message light on or off. 
The FAC is *21 for on and *22 for off. Dialing these manually works just fine.
The business extensions on all 3 PBX's use the NuPoint voicemail.
PBX 1 and 2 are clustered, 3 is not clustered because it's configured for the hotel.
3 is where the complaints are coming from.
The NuPoint is connected to #2.
Here is my config. If anybody can see my miss-step I'd appreciate the heck out of it.
    
Activating active configuration config=1 without Stoping TCP/IP
 NUPOINT VOICE SYSTEM CONFIGURATION
 
 Group #3: "DTMF out"
  Module 1: Lines 0:14
            Voice Recognition Conn: <none>
  Application = [DTMF TO PBX DIALER]
   Initial Dialtone Detect = [n]
   Access dial string = [T], Dial tone confirmation = [n]
   Pre-DN ON dial string = [*21], Pre-DN OFF dial string = [*22]
   Post-DN ON dial string = [+H], Post-DN OFF dial string = [+H]
   Suppress message light updates = [n], Wait for dial tone = [n]
   Alternate Code = [y]
   AT&T MWI = [y]
   Max PBX Message Count = 
 
        TCP/IP System Wide Host Configuration
        -------------------------------------
              Domain name: REDACTED.loc
 H  C  M  S
 o  a  o  l  N
 s  r  d  o  e
 t  d  e  t  t      IP Address       Host Name  
-----------------------------------------------------------------------------------------------------
 1  1  P  0  1   172.21.105.99     nupointmsngr 
 SmartHost : REDACTED.com
 ICP # 1
----------
 3300 ICP Name: vNuPoint.
 3300 ICP IP Address: 172.21.116.2
 Set Registration Code: ***     Set Replacement Code: ###
 HCI Reroute Hunt Group Number: 8099
  Number of extensions configured: 16
  Module Number   Channel Number   Extension.
   1      0   8001
   1      1   8002
   1      2   8003
   1      3   8004
   1      4   8005
   1      5   8006
   1      6   8007
   1      7   8008
   1      8   8009
   1      9   8010
   1      10   8011
   1      11   8012
   1      12   8013
   1      13   8014
   1      15   8016
   1      14   8015
 ICP # 2
----------
 3300 ICP Name: .
 3300 ICP IP Address: 
 Set Registration Code:      Set Replacement Code: 
 HCI Reroute Hunt Group Number: 
  There are no channels assigned.
 ICP # 3
----------
 3300 ICP Name: .
 3300 ICP IP Address: 
 Set Registration Code:      Set Replacement Code: 
 HCI Reroute Hunt Group Number: 
  There are no channels assigned.
 ICP # 4
----------
 3300 ICP Name: .
 3300 ICP IP Address: 
 Set Registration Code:      Set Replacement Code: 
 HCI Reroute Hunt Group Number: 
  There are no channels assigned.
  There are no ports assigned for the PIMG/TIMG 1.
  There are no ports assigned for the PIMG/TIMG 2.
  There are no ports assigned for the PIMG/TIMG 3.
  There are no ports assigned for the PIMG/TIMG 4.
  There are no ports assigned for the PIMG/TIMG 5.
  There are no ports assigned for the PIMG/TIMG 6.
  There are no ports assigned for the PIMG/TIMG 7.
  There are no ports assigned for the PIMG/TIMG 8.
  There are no ports assigned for the PIMG/TIMG 9.
  There are no ports assigned for the PIMG/TIMG 10.
  There are no ports assigned for the PIMG/TIMG 11.
  There are no ports assigned for the PIMG/TIMG 12.
  There are no ports assigned for the PIMG/TIMG 13.
  There are no ports assigned for the PIMG/TIMG 14.
  There are no ports assigned for the PIMG/TIMG 15.
  There are no ports assigned for the PIMG/TIMG 16.
  There are no ports assigned for the PIMG/TIMG 17.
  There are no ports assigned for the PIMG/TIMG 18.
  There are no ports assigned for the PIMG/TIMG 19.
  There are no ports assigned for the PIMG/TIMG 20.
  There are no ports assigned for the PIMG/TIMG 21.
  There are no ports assigned for the PIMG/TIMG 22.
  There are no ports assigned for the PIMG/TIMG 23.
  There are no ports assigned for the PIMG/TIMG 24.
  There are no ports assigned for the PIMG/TIMG 25.
  There are no ports assigned for the PIMG/TIMG 26.
  There are no ports assigned for the PIMG/TIMG 27.
  There are no ports assigned for the PIMG/TIMG 28.
  There are no ports assigned for the PIMG/TIMG 29.
  There are no ports assigned for the PIMG/TIMG 30.
 
  The following optional features are enabled:
   Cut Through Paging
   Configurable Data link
   Configurable Message Waiting
   NP Receptionist
   NP Forms
   Enhanced In-band
   Unified TCP/IP
   NP PWG View
   NP Call Director
   NP OnDemand
   Caller Line Id user interface
   NP RapidDial
   NP Config Server
   NP Admin Server
   LAN Backup
   UM-SMTP
   UM-WebView
   Record A Call
   IP Integration
   FPSA
 
  Prompt Language Configuration:
   English
 
 END
 END