Distribution Lists sending to incorrect recepients

When using Outlook 2003, when creating a distribution list with the
name DISTRIBUTION1, for example.

Adding contacts to the distribution list, etc.

When coming to send to the d list, outlook will recognise the name of
the distribution list, and auto complete the list in the TO field.

However, when sending the email, Outlook doesn't send the mail to the
contacts in the d list, but to the first contact it finds in the
Global Address List beginning with D. If the distribution list is call
MYDISTRIBUTIONLIST, it will send the mail to the first contact it
finds in the GAL beginning with M, etc, etc...

Any ideas?

Regards

Ben