When Old Agreements Attack. Sounds rather like the Apple/Beatles case... Law.com reports in "Putting a Legal Lock on 'Kryptonite'." From the article:

DC Comics filed suit alleging infringement, unfair competition and dilution of the trademark, as well as state law claims that Kryptonite Corp. was using kryptonite and other words containing "krypto" to confuse consumers into believing there was a connection between its products and the Superman legend.

The lock company counterclaimed for recision of its agreement with DC Comics, saying the purposes of the agreement had been "substantially frustrated."