1st Problem with Canon EOS 300D/Digital Rebel. Using available light (no flash) with shutter speeds of 1/1600 or higher, parts of my images are blacked out (like the mirror is not moving quickly enough). The black area grows with faster shutter speeds. This occurs in any mode (AV, TV, M) you can shoot at these speeds. Does it on multiple Canon lenses (85/1.8, 70-200 2.8L). Dealer had no clue. Canon support (no surprise) did not respond to my email and their tel help desk said I needed to send it in. Any clue?