Posted for "Dominic V Crain" <domcrain@tpg.com.au>:

 
 
 
 
 "Have you tried a different headset?  Perhaps it's the acoustic interaction
 of the mic and speaker in that location within the cockpit.  Try plugging
 into copilot side but sitting in pilot side or vice versa.
 
 Just a thought..."
 
 
 
 Yep - Done that - No speaker in cockpit.
 
 B..y irritating to say the least.
 
 Thanks
 
 Dom