If you experience very slow shutdowns after deploying a 2008 R2 member server in to a 2003 domain you might want to check the Page file at Shutdown option. If the option is enabled it can take 25 minutes or so to shutdown the server.
In order to disable this setting follow the below steps:
Select Start > run and type secpol.msc
Select Local Policies > Security Options > Shutdown: clear virtual memory pagefile
You should then find that server shutsdown in normal time
