It was probably cut and spliced by some unskilled hacks who work for Al Qaeda:
On the Friday before the sixth anniversary of 9/11, Osama bin Laden appeared in a new video, his first since prior to the U.S. presidential elections in 2004. In analyzing the video, Neal Krawetz of Hactor Factor, an expert on digital image forensics, said in his latest blogs that the video contained many visual and audio splices, and that all of the modifications were of very low quality.
Most striking is bin Laden's beard, which has been gray in recent images. For this video it is black. "As far as my tools can detect, there has been no image manipulation of the bin Laden portion of the image beyond contrast adjustment. His beard really does appear to be that color."
Krawetz says the inner frame of bin Laden was resaved at least twice, and not at the same time. The images show fine horizontal stripes on bin Laden and a background indicating these came from interlaced video sources. In contrast, the text elements, such as the As-Sahab logo, appear to be from non-interlaced sources.