I have a Sony eReader PRS-350. According to this site, it is equipped with the DRM enabled software that should allow me to download books from libraries. I downloaded the digital editions 2.06. First I could not authorize my computer, and found out that my computer had authorized itself, so I went through the de-authorizing and re-authorizing thing. Now I cannot download any books I have downloaded from the online public library to my device. Adobe Digital Editions registers my device there. I can look into it through ADE to see what books are there, all that works fine. Yet when I try to move the downloaded book INTO my device, it tells me there is no record of a loan on the device. Now when I go to "Add to Library", it will not even see the books I have downloaded. The books are in .ascm format. What is going on? Very dissapointed.
I had very similar. I found a few ways of getting books onto the device that may work for you:
depending on how you work or what readers you have, one or another may be convenient.
The .acsm file is a sort of DRM pointer to the real file, and the real file is a .epub file.