From GameBrew - a wiki dedicated to Video Game Homebrew.
Utility homebrew to repair/correct the defects of ghosting that appears on DSi. Ghosting is a replica of the transmitted image, offset position, which is superimposed over the main image on analog broadcasting.
This software attempts to remove the ghosting by cycling the brightness of each pixel in much the same way that this problem can be corrected on a plasma TV.
Load DSiXL ghostbuster.nds and leave it running as long as possible, it will send the DSiXL Into a sleep mode.