If your client's print jobs don't get deleted after printing, you may have removed the CREATOR OWNER entry from the printer permissions.
Click Start / Settings / Printers and right click on the printer. Select Properties. On the Security tab, click Permissions. If CREATOR OWNER is not listed with Manage Documents, add it.
You will need to reboot your print server.
Note: While you're here, insure that Administrators have Full Control.