"To" and "cc" fields appear empty in received mails

[Fernando Socas]

Hi everyone,
From a couple of days ago, all the mail messages we receive appear with
empty "To" and/or "Cc" fields.
If I try to "Reply to all", it replies only to the mails in the "From"
field, and not to the mails in the "Cc" field.

We're using Outlook 2002 and 2003, connected to Exchange 2003 with SP2.

Any help is welcomed.
Thanks !!!