Microsoft officially does not support using BCM with an Outlook profile that
includes an Exchange account, unless that account is on a Small Business
Server 2003 machine and you have installed the corresponding patch for BCM
from http://support.microsoft.com/?id=831747. If you add a BCM database to a
profile that includes Exchange from any other environment, the next time you
start Outlook, BCM will remove the database from the profile. However, as
described at http://www.outlook-tips.net/howto/bcm.htm, it is possible to
install the patch and then hack the registry to make BCM work with a profile
that contains Exchange even if it isn't SBS 2003.