asterisk users - Apr 2006 - Asterisk to Linphone sound playback delay, and then choppy

Hi, 
  
  I've got this PXA270 board set-up with Linphone 1.2.0 and am trying to get
linphonec to work with Asterisk.
  
 I have the echo test working, but when I dial in to this, to voicemail or
anything else using Playback() to play a sample, I hear nothing for ages (10-15
secs) and then little sections. With the echo test, I get the tail of the
message (...pressing the pound key........pressing the pound key...) echoed
rather well, but sound quality is a little poor.
  
  I have Sipomatic tested over the same cross-over network connection...
perfect.
  I have made calls to my mobile via SipGate... takes a while to start, but then
perfect.
  
 I thought it might be because I was using OSS emulation, but I recompiled to
use ALSA pure (without 'Jack', that had issues) and got the exact same
results.
  
  Does anyone have a working config they could post, or any idea what may be the
issue?
  
 I am running Asterisk on a 1600Mhz laptop, so I doubt it's short of cycles
- and I don't think I did anything special as regards config.
  
  I used this as a template for the linphone config 
  http://www.voip-info.org/wiki/index.php?page=Asterisk+phone+linphone 
  
  I've tried the apt-get asterisk (1.2 I think) on Debian, and also this PXE
version (booting my laptop from the board)
  http://www.automated.it/asterisk/pxeindex.html 
  
  And this as a starting point for my Asterisk config files. 
  http://www.automated.it/guidetoasterisk.htm#_Toc49248767 
  
  Regards, 
  
  Adam