I have a Sony PRS-T2 ereader. When I transfer ebooks that I bought from the Kobo bookstore to my ereader, I can't open them because of Digital Rights Management. It appears that my computer is authorized with my Adobe ID, because I can read the books on my computer. However, my ereader itself isn't authorized, and it won't accept my Adobe ID. Go figure. I know I'm using the correct password for my Adobe ID, because I can sign into Adobe.com using them.
It's my problem too. Adobe helpdesk is not very hulpfull (to put it mildly). I'm afraid the other problem is the Sony PRS-T2.