Help: how to remove all disconnected principal ??

hello,everyone:

     Has anyone can tell me  how to remove all  disconnected principal .  Our windchill 9.0 M050 is integrated with AD ,AD authenticate the users who log in Windchill. AD administrator deletes some users in AD,so  there are some disconnected principal in Windchill.

    I  log in as wcadmin(site administrator) and enter into site-utility-principal administrator-maintainance page,when I check the disconneted principal and click the "delete" button ,it shows"LDAP erorr code 32 No Such Object"

     Firstly，I am very sure that these users  are not in our AD.

  (1)  I view the WTUSER table :select t.name,t.ida2a2  from wtuser t where t.repairNeeded=1  and there are disconnected user who are shown in the above web page returned,I also check the remoteobjinfo,remoteobjid table   there are disconnected user who are shown in the above web page returned

  (2) I check the Aphelion brower  the disconnected user  entries  are also in there

  so  I cannot  delete the disconneted users in the Windchill web page  and   I  dare not  delete the  user entries in the WTUSER table directly.  Now  what can

I do to  delete the disconneted users.

   Thanks for your reply.