Ambac Suing Everyone In Sight?

Ambac sues Bay Area Toll Authority...

+

$400 million was the original size of the Ambac bond issue I mentioned below (CUSIP 023139AF5). All of it is still outstanding and the interest payments are issued twice a year, which means that Ambac couldn't even make an interest payment of $12.3 million, originally due on 15 August 2009.

The strange bit is no one has mentioned this technical default anywhere else. On the FINRA site, the bond isn't even labelled as trading flat - just a subtle mention of a 0% yield.

Am I sadly misinformed - or does its book value of negative $18.80 speak for itself?