This is linked on globalsecurity.com, Sunday’s NYT:

WASHINGTON, Sept. 11 – President Bush and his top advisers have received intelligence reports in recent days describing a confusing series of actions by North Korea that some experts believe could indicate the country is preparing to conduct its first test explosion of a nuclear weapon, according to senior officials with access to the intelligence.

http://www.nytimes.com/2004/09/12/international/asia/12nuke.html