Today Canon sent this info out about a new firmware update to address ghosting and double imagery in continuous shooting mode. Here is a direct quote from the translation page.
It’s a chuckle.
“If the continuous shooting, the scene is one of the images overlap part of the picture frame before the next shot, they may become crowded and afterimage Ballmer.â€
“I do not know in most exposure image, the afterimage when the stress level of image correction and retouching process is easy to stand out.â€