I have a test domain where my 2 x 03R2 DC's were primary. I then prepped the domain for 08R2, which went fine. I then promoted the 08R2 machines to DC's, and then transferred FSMO roles etc. Everything went well. I then demoted the 03 servers so now I have 08R2 DC's as well as raising the forest and domain functional level to 08R2.
When my test clients to the internet, it takes a long time to resolve things, in fact, even on the DC's themselves it takes a long time.
What could I have done wrong?