Made sure all SP's and fixes are up to date on 2000 exchange/server. Only server in our environment. Ran the Inetorgpersonfix.ldf script which ran successfully, the ran adprep /forestprep and /domainprep which both completed sucessfully. Getting error when trying to add 2003 as a domain controller to the existing forest "The version of active directory schema of the source forest is not compatible with the version of AD on this computer."
Referenced Articles Q325379, Q285172, Q314649 among others to no avail.