From the press release from the minority (i.e. the Republicans) on the House Oversight Committee:

“My staff’s investigation reveals that President Clinton’s former National Security Advisor Sandy Berger compromised national security much more than originally disclosed,” Davis said. “It is now also clear that Mr. Berger was willing to go to extraordinary lengths to compromise national security, apparently for his own convenience. “The 9/11 Commission relied on incomplete and misleading information regarding its access to documents Mr. Berger reviewed. No one ever told the Commission that Mr. Berger had access to original documents that he could have taken without detection. “We now know that Mr. Berger left stolen highly classified documents at a construction site to avoid detection. We know that Mr. Berger insisted on privacy at times to allow him to conceal documents that he stole. One witness with a very high security clearance believed he saw Berger concealing documents in his socks.

There’s more here, including a link to the full report.