Found this on another forum. Are you getting a green light while it's delaying showing the picture? Some of the suggestions were mentioned others not. The D-Lighting apparently is a frequent cuplrit.
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That blinking green light tells you that the camera is still writing the image to the memory card, so it's not a matter of slow display but a matter of slow writing. I will assume that you are using the same memory card you used before the problem started. Memory cards DO come in different speeds and you do not want a slow card. You want 30MB/sec (200X) or faster for decent performance.
I hate to mention the obvious things, but it's a start. Is your battery getting low on charge? Did you change the file size from small to large? Are you shooting RAW or TIFF?
The less obvious things would be a change to something like adding a comment to the image, using Active D-Lighting, noise reduction, using image verification...
It also occurs to me that you might be having this trouble outside. It's getting cold out there and that will slow things down, too. Keep your camera close to your body when it's not up to your eye to keep it warm.
It may be time to dump all of the images to your hard drive and format the card so you start with a clean slate, too.