I suspect you may be mistaken. As far as I know there was no special dividend on common shares of NCZ.
Perhaps what you saw was the October 1st announcement of the next regular dividend. The ex-dividend date was October 9th, the record date was October 11th, and the dividend will be paid on November 1st. You might want to check the October 1st press release on either Google or Yahoo, or check the Allianz Global web site.
The dividend that you saw in your Sharebuilder account was most likely the dividend that was paid on October 1st. If you owned NCZ at the close of the market on September 10th you would have received 0.085 for each share of NCZ you owned, payable on October 1st. Sharebuilder probably credited it to your account on October 2nd or 3rd.