I too have had this problem, with books I have bought via BooksOnBoard - if I download to ipad onto Bluefire app they are fine. When I came to move my ebooks to new Kobo Glo in late Feb, these DRM ones didn't work - used ADE, did it all as said - no joy. Have spent time on Adobe and Kobo help - latest from Kobo was to Reset the 'Adobe GB Licence' attached to the books - not sure at all what this means (BoB say not licence attached to books) so will be going back to Kobo.
I think it is a problem between the ereader and ADE as the .acsm file link remains pointed at the .epub file on the desktop pc and not transferring over to the ereader.
Using the Kobo internet access, I cannot access BoB as their mobile site just freezes on me - this could be an answer for me if I can get access via the ereader and miss out going via the desktop - otherwise I'lll be loading these files back onto the ipad.
Very frustrating and will probably dictate where I buy books from in future (ease of download versus cost)
If I end up with a solution I will post!