problem with distribution lists

[JP+]

I have imported conatcs from Outlook 97 to Outlook 2003, I
exported to PST and then imported to 2003

Now when sending email from a distribution group Iwe get
error "Internal support function not supported error" I
have tried creating new distribution group but got same
error.

The only difference with outlook 97 and 2003 setup is that
97 was setup as corporate using Postoffice and 2003 is not.

thanks

JP