Nested Distribution Lists in shared contacts don't work
 

We have an AD user that has contacts that are shared by several people. The
contacts list contains several nested distribution lists, as emails need to
be sent to hundreds of people and Outlook/Exchange seems to have a limit on
the # of contacts allowed in one Distribution List (DL).

Although working fine until a week ago, now if a user tries to send an email
to one of the nested DL's, the nested info will not expand out into actual
email addresses (i.e. the 2nd level of the nest has no (+) symbol by it, and
clicking on that DL name just brings up a box with SMTP address UNKNOWN).
What has changed on out system? User mailboxes were moved last weekend into
new groups on the Exchange 2003 server, as well as from a local hard drive to
a SAN drive.

How can users continue to be able to send to large distribution lists???

Thanks