We have two 2003 DC's. For some reason only one can manage theExchange properties of a user's account. I have view advanced features on. One of the admins said that abilty was there recently. We have exchange 2007 and exchange 2003 in the network. The other problem is from within the Exchange 07 management I can't change which address I want to make as the primary address. I would be happy to be able to fix either issue. Thanks for any help.

Are the exchange tools installed on the DC"s for the 03 mailboxes? Try re-installing. Also, you can't use ADUC to manage 07 mailboxes. For changing the primary SMTP address in 07 its: set-mailbox http://technet.microsoft.com/en-us/library/bb123981.aspx use the -primarysmtp switch