If you bookmarked your page before you reset the Cybook you would still be able to get back to where you were when you boot up again. Not remembering what book you were on would only happen if it was the first time you went into that eBook or if you had just gone back to it after looking at another eBook. I'm not sure I see an advantage to this though since you would still have to wait through the entire boot process when you want to read again.
Clicking reset to freeze the last page view was suggested as an option if you wanted to display a picture on your Cybook when you weren't reading. Bookeen even sells
frames for this purpose on their website.