Samsung Display and LG Display had been fighting over display patents for a long time - with lawsuits launched by both sides and even accusations of stolen prototype TVs. In February 2013 the two companies agreed to resolve their OLED dispute and they even considered cross-licensing patents. Later in September 2013, they dropped all OLED lawsuits against each other in a reconciliatory gesture.
But the latest report from Korea is that the LG and SDC failed to negotiate a settlement. SDC wants to reach a patent cross-licensing deal, but LG is not interested. I think this may be because LG believes its WRGB technology is superior (and indeed they are much more advanced in their OLED TV efforts) - and perhaps Samsung is interested in adopting this technology for their OLED TVs as well.
It's not clear whether the talks broke down completely - we'll probably know soon if we'll see new lawsuits filed by the two companies.