El Copyright Del Mundo Invisible

Maroual writes in with the following question:

Could the Gala-Salvador Dalí Foundation send a C&D letter?

… and refers to this post he made on the Zäppî forums:

The Zappa Wazoo liner notes mention “Cover Art ‘Mundo Invisible’ (oil on canvas, 60″ x 72″) by Christopher Mark Brennan, 2003″ which itself is a derivative work of the excellent Slave Market with the Disappearing Bust of Voltaire (oil on canvas, 46.5″ x 65.5”) by Salvador Dalí, 1940.
Actually I was curious to know whether any permission was needed and/or requested to the Dalí Family Trust (la Fundació Gala-Salvador Dalí) prior painting and then publishing. This painting should not fall in the public domain before 2010 thanks to the copyright extensions, right?
Does this constitute a copyright infrigement? Does this respect the original intent of the painter?

Heh heh!