Why would lines appear across a photo taken on a digital camera?

Whevever I view a photo there are lines across it that make it look like the photo has been taken through a venetian blind, as in there will be a stripe that looks as the photo should be and then the next stripe makes that section of the photo look in shade, and so on all the way down the picture. The lines don't show when the picture is being taken and this happens when the camera is set to auto.please help! Is this a fault or am I doing something wrong!

It sounds like there is a problem with the display, check to see if it happens when you set the camera to manual (macro etc) Also do the lines appear when you print? If not then the camera is faulty. There's a problem with the camera. Is this a camera phone? Possibly a low light condition. Use a flash or brighter conditions and see if you still get the lines. Camera fault - if it's in guarantee then send it off for repair or take it back to the shop.

Check the photos on your computer - if they look OK there then it's the screen on the camera that's faulty. Well, let's state the obvious first, check the lens for dirt and debris. If that's not it, I believe your CCD may be dirty or bad. Unfortunatly repairs on digitals are substantial, and you should just consider replacing it. It sounds to me as if there's a problem with the camera itself (unless these lines happen after printing, in which case it's a dodgy printer, but that doesn't sound like what you meant).