If you position the screen too far down the preview window will screw up and when you cancel out of the screen position menu the picture will show up in the top left hand corner of the screen instead of the entire screen. 1) Watch a high def sat channel and go to the screen position menu under system preferences->view preferences->more. 2) Select the move screen down option and hold the select button. 3) The screen will slowly move down and after a minute or two it will hit the max offset. 4) Select reset to recenter the picture. 5) Select the move screen down option again and hold the select button for about a minute you'll see the video preview window jump to behind the graphics. 4) Hit cancel. The video will be in the top left hand corner and you'll see a gray box beneath the video. 5) Switch channels. You will see the gray X screen of death accompanied by flames shooting out of the back of your 921. I've seen the video do this before doing other things but I was never able to reproduce it. This however, will crash the 921 every time.