asterisk users - Nov 2009 - UK Vodafone messaging, ISDN, Wrong CallerID being used.

I've a strange problem with CallerID when calling Vodafone mobile's from
my Asterisk Box.

If I dial out on my ISDN-30, setting the CallerID to my DDI (XXX802), a
Vodafone mobile correctly shows the incoming call with this number and
if the phone's not answered it shows a missed call from XXX802.  All
very good.

However, if the call is not answered and goes to the Vodafone messaging
service and the Vodafone user then uses the 'call back' option, they end
up ringing back on XXX800 (which happens to be the lowest number in our
range and the billing number for our ISDN-30).

How are Vodafone getting *TWO* CallerID numbers for the same call?

Anyone know a way I can stop this happening?

TIA.

-- 
 Regards,
     Russell
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| Russell Brown          | MAIL: russell at lls.com                     |
| Lady Lodge Systems     | WWW Work: http://www.lls.com              |
| Peterborough, England  | WWW Play: http://www.ruffle.me.uk         |
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