I have 2 servers, 1 running Server2003 R2 SP2 and the other running Server 2008 SP2. We have 30 Mac users (mixture of Leopard (10.5.8 and Snow Leopard 10.6.7) who connect to shared folders on both servers and the problem they are having is that once they open up a file from within a sub folder on either server, close the application and attempt to move the parent folder (i.e. as it shouldn't be that folder, it should be located in another section on one of the shares) it will not move as the folder is showing as open in "open files".
I have tested with both servers, created a test share, duplicated some of the data and completed my testing from there. I have used multiple versions of OS X 10.5 and 10.6.