Infowars.com has a story posted with links to a document that confirms Norman Mineta's testimony that Cheney issued a stand down order, as what is believed to have been Flight 77 approached the Pentagon.
The document, which was obtained by John Farmer through a Freedom of Information Act request, is composed of handwritten notes written by 9/11 Commission staffer, Miles Kara. It is based on a Secret Service timeline. Although the Secret Service refused to turnover the original document, Kara was allowed to view it and take notes.
The document can be viewed here: http://bluecollarrepublican.files.wordpress.com/2011/02/t8-b16-misc-work-papers-fdr-secret-service-timeline.pdf
The significance of this, is that it means the 9/11 Commission was aware of the stand down order, but chose to withhold this information. The article speculates this decision may have been taken in order to protect Cheney.