I know this sounds familiar and I had read about it before. Long search but I found it, the text book publishers claimed they could reuse images and also that they were overprinting past the license because they didn't accept the limits of the contracts.
November 2010
http://www.pdnonline.com/pdn/news/After-Flouting-Print-1163.shtml"The scheme that Houghton employed was to license for the lowest amount it thought it could get away with, and then print whatever it wanted," Seidman says. One HMH executive said in a court deposition that the publisher ignored print run limits in its photo licenses as meaningless numbers.Meaningless numbers?