asterisk users - Jul 2005 - GnuGK Nufone H323 -HEAD - Prefix issue

Greetings-

As most of you who monitor this list know, I've been messing about
with Asterisk -HEAD, Cisco Callmanager, and the nufone H323 channel
driver here for some time- with pretty decent success.  I'm hoping to
cash in a chip here- I've run into something that is probably a very
simple answer, yet not found a decent reference to resolve it.

Scenario-  -HEAD as of last week (generally, up to date), latest
acceptable versions of openh323 and pwlib (based on the chan_h323
channel driver instructions).  GnuGK v2.0.8 gatekeeper.  Everything
works swimmingly outbound from asterisk, and inbound as well, so long
as I use e164 matching.

The prefix= directive, however, seems to not work at all.  While debug
shows it adding my specified prefixes, gnugk's output does not show
them listed.  If I go with specific e164 directives, gnugk shows them
fine.  Net effect, using prefixes, I cannot get calls in to Asterisk-
gnugk cannot find the proper registered gateway for the call, and
fails the call at the gatekeeper.  So far as I know, I've got
everything configured properly (h323.conf below)- I'm leaning towards
needing an upgrade of gnugk.  I've got no major issues with this, I'd
just rather not break what's currently working.

Anyone out there have any clues they can share?
;
; Configuration file of OpenH323 channel driver
;

[general]
;
; Port to listen to
port=1720
bindaddr=XX.XX.139.59
gatekeeper=XX.XX.131.112  
disallow=all
;allow=g729
allow=ulaw
context=tbr-extn
UserByAlias=no
noFastStart=yes
dtmfcodec=101
noH245Tunneling=yes
;
; Specify alias(es) of this host.
; It may be used multiple times.
;
alias=tbrmtp
alias=689
;
; Set the context of H323 calls
;
[tbrmtp]
type=h323
context=tbr-extn
prefix=689,688,687,686,685,684,683,682