asterisk users - May 2004 - Problems Retrieving Voicemail Remotely

I am having problems retrieving voicemail from outside the asterisk system.
My extensions.conf is configured as follows:

exten => 7900,1,VoiceMailMain2(s${CALLERIDNUM})
exten => 7900,2,hangup
exten => 7902,1,VoiceMailMain2
exten => 7902,2,hangup
exten => 7999,1,dial(sip/7999,20)
exten => 7999,2,voicemail2(u7999@incoming-pri)
exten => 7999,102,voicemail2(b7999@incoming-pri)
exten => 7999,103,hangup

I have the phone call 7900 to leave voicemail and have the messages button
programmed to 7900 to check.  This works great.  I dial 7902 from 7999 and
it gives me the voicemail menu and I can input my number and password and
that works fine.  When I dial either 7902 or 7900 from an outside PRI line I
get the voicemail menu but it does not appear to accept the digits that I am
keying in for the extension:

    -- Remote UNIX connection
    -- Executing VoiceMailMain2("Zap/1-1", "") in new stack
    -- Accepting call from 'my calling number removed to protect my
privacy'
to '7902' on channel 1, span 1
    -- Playing 'vm-login' (language 'en')
    -- Username not entered
    -- Executing Hangup("Zap/1-1", "") in new stack
  == Spawn extension (incoming-pri, 7902, 2) exited non-zero on
'Zap/1-1'
    -- Hungup 'Zap/1-1'

I originally had the line exten => 7092,1,Ringing and exten =>
7902,Wait(2)
included above the config but when I dialed from the outside with these
lines enabled I would get ring no answer and the PRI would lock with that
call attempting to come in.  I would then have to restart the Asterisk
services.

Can someone let me know what I have done wrong?  I am at loss as to where to
go from here.