One of the reasons why this matters is because the United States didn't really live up to its promises to North Korea in the 1994 agreed framework. To be blunt, they were supposed to get light water reactors and enough know-how to run them, and that didn't really happen. It kind of sort of happened, but the United States dragged its feet, confident that it just needed to buy time until Kim Jong-Il's regime finally, inevitably, fell.
It hasn't fallen.
That's why things are so screwed up right now. That, and Japan's fierce (and understandable) outrage over North Korea kidnapping Japanese to teach Japan's language and culture to North Korean agents, but the basic justification is the North Korean "cheating" serving as a justification for America neglecting its own promises, thus allowing NK to charge that the deal was already broken.
Hindsite is 20-20.