Usually when the camera is in a power saving mode, the photos don't stay on the display for very long. I'm not sure if you can change the length of the display after the shot, but if you can you would just need to increase the time. As for the other issue, if you can reset the camera to it's original defaults, I would do that in case you accidentally changed a setting somehow. If you download the images to a computer, do the images look okay? I'm not real familiar with the PowerShot A4000, so I'm hoping someone who has one will be able to help you.
Steve M.
