I have an old Server 2003 machine that has been acting as the domain controller for the network. I installed a brand new Server 2008 R2 machine, joined it to the network, ran adprep32 on the old server to prepare it so I could elevate the 2008 server to a DC. Did all of that and it was successful. I transferred all of the FSMO roles over from the 2003 to 2008 server successfully. I changed the DNS settings on each server so that it points to the new 2008 DC first then the old one second. My Exchange 2010 server (separate 2008 R2 machine) works fine as long as the old 2003 DC is up and running. But once I shut it down, mail stops working. If I try to go to OWA, it lets me log in but then I get the message "A server that contains information about your user account and mailbox can't be found." It looks like the Exchange Server is not looking at the new DC.