asterisk users - Aug 2004 - Can't get T or t option to work with two IAX2 channels.

I have this in my dialplan:
exten => 6,1,Dial(IAX2/rious@NuFone/16162180431,30,rTt)
A call comes in via NuFone over IAX2.
The caller presses 6.
The dial application calls my cell phone.
If I press # on either the calling phone or the called number, nothing
happens.
I have notransfer=yes set in my iax.conf.
I can see both calls with show channels the entire call.
If I do an iax2 debug, I can see the # keys being pressed as dtmf messages.
But I never get to transfer the call.
I have gotten it to work if I call from another asterisk box console to my
main asterisk box, instead of using NuFone.

I can include any files which might help diagnose the problem.
Thanks,
Chris Samuelson
rious@rious.net