The Elixir pipeline at CFHT processes each MegaCam image. It does an excellent job of detrending (bias-subtracting, flat-fielding) the images. However, the astrometric solution Elixir provides is only good to about 1 arcsecond. To combine the images, they must be aligned to better than a pixel. One arcsecond accuracy is insufficient. Therefore, it is necessary for a user to devise some way of aligning the images to higher accuracy. This is not an easy task, and rendered more difficult by the distortion of the MegaPrime focal plane. The problem is not intractable and there do exist a number of software solutions to the problem, but it remains an obstacle to easy use of MegaCam data.