I have had my D5000 since January of this year, when I bought it, I picked up an 8gb memory card, a ScanDisk Ultra 15mb/s rating. Within the last week or so, it has started taking 10-15 seconds to write long exposures to the card, and when I go to multiple release mode, it tells me I only have 2 pictures remaining, and when I hold the shutter release down, it slows down very quickly. I am wondering if the problem is with the card, or the camera? Files transfer from the camera at the same rate they always have, so I am led to believe it may be the camera? Thank you for any help you may provide.
When using Long Exposure Noise Reduction, the camera will capture a second image using the same shutter speed and use the second image to find the noise and remove it from the first image. In effect doubling the processing time and significantly reducing the capacity of the buffer. Good Luck and Enjoy your Nikons!