George,

In doing a little research recently on Odd Nerdrum, who appears to be in trouble with Norway's tax authorities, it was reported in a 2011 court case, Nerdrum claimed that the technique he used in the 1980s was faulty, "a special mixture of oils and paint in an effort to recreate the style of the old masters" which subsequently melted and disintegrated.

And a further explanation from his wife, Turid Spildo in which she states in a blog referencing the above problems, "The mastic that he and his students had experimented with was not good. Later, he realized that the mastic probably was from young trees and not from old trees like it always had been before… Because of this the resin triggers a meltdown …
When the Accused rose on the third day, he had decided to re-paint all the paintings from this decade. Without the mastic of course. I imagine he threw all the mastic in the trash that night. I remember a student a few years later who was curious about this oil mix. Odd paled and told him that he should never ask about that again nor should he ever think about it again."

Evidentally, Odd was preparing for painting failures on a large scale from his work in the 80's, in his court case, he refers to keeping sums of money for possible compensation for failed paintings.

What occurs to me from the above references is that we hear of one of the greatest painters of our time, struggling with the effects of soft resins in mediums. This should make those that have employed the so-called, "Rubens style or Flemish style medium" using the Maroger formula of leaded linseed oil, mastic and turpentine, at least consider some of the ramifications of this usage. Now one further thought is that his paintings are on canvas. Would he have this same problem if they were done on panel? I would think a rigid substrate might offer some protection against the apparent delamination.