Well it has been a long time since I put this on POTN. I could not find it here so either if fell off the end of the earth, or I suck a searching.
Let me introduce you to CanonNumFix
(125k). When you run the program, it displays the following.
This program will create folders and empty image files that match the layout for most canon digital cameras. By setting your camera to automatic reset and formatting a fresh flash card, you should be able to simulate a card with a determined number of pictures and thereby trick the camera into believing it has taken that determined number of pictures. Once you have run this program you can set the camera back to continuous numbering.
Hope its of use to you. Wait till you see the date on it. Sorry this is for the PC only. I just tried it out on Window 7 64bit and it still works, even across the network. Enjoy.



