Upon booting up, my computer often asks me to give the password for the keychain System. It will not accept my administrator password. If I go to Keychain Access, I cannot get it to show the password; it will not accept the administrator password as the keychain password, and I know no other. I am sure that I never changed the keychain password, so I don't understand why this is happening. Is there any way to retrieve the keychain password, or to leave the System keychain unlocked?