Raising domain function level WinServer 2003 to Win Server 2008

I am getting an error message when I attempt to raise a domain functional level from Win Server 2003 to Win Server 2008. Please see the screen shot. Please help me to solve the issue. Thanks in advance.

Raise domain functional level
The functional level was raised successfully. The new functional level will replicate to each Active Directory Domain Controller in the domain. The amount of time this will take caries, depending on your replication topology.
