Best way I've discovered to kill the moire pattern is to scan it at the max resolution your scanner can do in hardware, or (say) 600dpi if you can do more. Then use the Gaussian blur filter to blend the haltone dots togeather, something around 2.2 or so pixels should be right, you want the point where the dots disapear, but you don't loose a lot of detail. Then resize it to about 1/2 or 1/4 that size. The whole idea is to blend the halftone pattern back into pixels.