asterisk users - Oct 2003 - another newbie question: forwarding delay?

Hi, Most embarrased newbie evere here again.

Possibly another daft question.  I have the digium
starter kit lite, so I've got the single FXO and FXS lines

All is working well with local sip phones able to dial other phones,
conferencing, MOH (Thanks Asterisrk-users list!) along with the one
analogue handset etc etc.

The one niggleing problem I have now is this:

My Dialplan is set to ring the Analogue handset when there is an
incoming PSTN call.  Fine.  This works well BUT there is an annoying delay:

I've left a normal analogue handset on the PSTN line, so we have the
asterisk internal analogue and the external analogue next to each other.

Ehen there is an incoming PSTN call, the external analogue phone starts 
ringing about 3 seconds before the internal one. If I answer the call on
the external handset (ie not via *), the internal phone keeps ringing for
another three seconds or so.

I'm pretty sure that I've not got an intentional delay anywhere.

Does anyone recognize this problem? Perhaps it's just related to
fiddling (answering!) the esxternal line before it hits *?

I won't fill up the list with my silly dialplan, but its here if anyone
cares to check if I've stuffed it up!  
https://www.turbotas.co.uk/wiki/index.php?page=TurboTasExtensionsConf

Thanks in advance!

Toby.