asterisk users - Dec 2006 - Requested transfer capability: 0x00 - SPEECH - How to change to 31KAUDIO?

Hi everyone!

I'm having an issue calling the Numbers Information Service (similiar to 411
in the US) in my country.

I use: TE110P, connected to a PRI line running on an E1.

Besides that specific number, all calls pass through fine, in and out, no 
problems whatsoever.

I called my Telco, and the guy did a comparison of my PRI call setup, and 
other calls that pass through and get fine to the Numbers Information 
Service. The only difference he could find, is that every other PBX in my 
country (mostly proprietary ones, I would assume...) - Request a transfer 
capability of 31KAUDIO, which I assume means 3.1KHz audio. I also assume 
"SPEECH" is actually 8KHz., which is more, and probably with higher
quality.
The guy at the telco said it may be the problem, maybe because the end system 
cannot "reach" the desired voice quality, or whatever (he never
encountered
that problem before...)

I called Digium's hardware installation service, and they told me to change 
prilocaldialplan to "unknown" (I had it set to "local"
before); I am not sure
how this is related, because it seems to me not related to dialing at all - 
but Digium made the software and the hardware, so they must know :-)

Anyways, that advice didn't really much help - my calls are still going out 
requesting SPEECH:
    -- Requested transfer capability: 0x00 - SPEECH

Anybody has any advice on how to change this?

Thanks!

-- Shimi