[Asterisk-Users] Asterisk Guru help needed for DISA troubles

[Jeffrey Starin]

I have a setup which allows users to access my asterisk box via FWD.  
That is, a user in say, France can call into a local access number for 
FWD, then hit number 7 which dumps them into a DISA request for a 
password, which then dumps them into my internal extension so they can 
dial out through a VOIP provider.  Everything works fine until they 
enter their tones for the number they are calling -- DISA does not 
respond, just sits there twiddling its thumbs.  The strange thing is 
that it works fine when a caller direct dials into my Asterisk box then 
they can access the internal extension and dail outward.  So, I'm 
presuming this has something to do with codecs being passed from the FWD 
server(s).  For FWD I have (in addition to other settings):

disallow=all
allow=ulaw
allow=alaw
allow=gsm
allow=ilbc
dtmfmode=inband

and for the VOIP provider for calling out I have

disallow=all
allow=ulaw
allow=alaw
allow=gsm
allow=ilbc
dtmfmode=inband
dtmfmode=inband

Why would Asterisk understand the tone for transfering to the DISA 
extension, but stall with any subsequent tones, yet work 100% for a 
direct dial inward call?

I'm perplexed.

Thanks for any insights a guru could provide.

B.