Delegate Permission in Windows 2003

Hi,

I have been trying to delegate permission to a user to have “unlock locked accounts rights”. I right click on the interested OU in AD and choose Delagate Wizard…went through and completed the entire process. However, the user still NOT able to unlock locked accounts or reset password in AD (we had tried both on DC and Adminpak installed locally on his PC). He gets the “Insufficient rights to perform the operation” when attempting to unlock/reset user account

Is there anything else I should have done for it to work..give assist. Your help is urgently needed.

Thank you