You can view the video. It is linked from Drudge's page.
Video here. Black X appeares at about 1:25.
http://dailydissent.org/video/cheney112105.wmv
According to a link on Michele Malkin's site, that video was apparently altered from the original. Go to her site for the real scoop.
There no indication from that video how long the X event lasted. Do you know?