North Korean "Bumper Crops"
The blog "Kushibo-E-Kibun" has a good analysis of the latest proclamation from North Korea that it won't need aid due to "bumper crops."
The claim is likely faulty, and the Potemkin view of happy peasants and soldiers havesting crops shown to journalists "at a distance" is probably staged.
It appears clear, however, that the North Korean regime does not wish to be a dependency of outside parties, even if many of its people starve.
The North Korean regime is all about control. Despite the talk of economic reform (now curtailed to some degree), what the North Korean leaders want is to maintain their absolute power at all costs. If outside aid is what's needed for that control, they'll take the aid. If the aid is undermining their control, they'll bar it. It is as simple as that.
Kim Jong-Il and his cronies will kill half the people in North Korea if it means they get to keep prison-like control of the other half (my apologies to normal prisons, which usually have much better conditions than North Korea).