I have finally (after hours resolving multiple, separate problems with this software--just like every single time I am forced to use it) finally managed to get my book to appear in Adobe Digital Editions, and my reader device to be detected by ADE. I can even drag and drop (horrible interface) the book from my "library" onto the reader device which attempts to transfer the book to my device.
I can read the book on my computer. I can open it, both from the library on my computer and from the library on my device. But when I close ADE, safely remove my device, and power it up, the book appears as one page long, and that page appears as "PAGE ERROR" on my device.
If I then reconnect my device to my computer there are two possibilities, since I've tried this so many times. The first is that the book still appears fine when loaded from either library. The second is that attempted to load the book from either location will cause ADE to crash. At that point, I delete the book from either or both libraries, reopen the ASCM file to get the epub back into my ADE library, and try again, inevitably failing for the same reasons.
So, what exactly does it take to get this software to really transfer a readable book onto my device, rather than merely pretend to do so?
Well let me ask you this: Are you using a Sony eReader? If so, it is likely that there is a chapter that is over 300kB, which is apparently a limitation for older Sony devices. If a book does have a chapter over 300kB, apparently when you open the book on your eReader, the page will show a triangular shape with an exclamation point in the middle of the triangle with the words below it it "Page Error!"
I'm sorry that this doesn't help.