Isilon Automatic Home Drive Creation issues with DFS

We are creating automatic homedrives for different department users. These departments are segregated and they all have their own home drive share with automatic variable expansion. We also have DFS on top of these homedrive shares. We started noticing weird issues and the homedrives are getting created in different areas. Even though the user1 is mapped to Dept1Home we are seeing folders with  created on Dept2Home. Is there anyway to configure isilon to only create homedrives when access is successful and not for users whose access fails?