Unable to read E-Book on Authorized Device

I am unable to read the books that I transfer to my kobo reader through ADE due to an authorization error. However, I can see that both my computer and my kobo reader are authorized under the same account (my personal account). I can confirm this by going to the 'Help' menu and seeing the computer's authorization, and clicking the 'Settings' option when my kobo is plugged in and viewing 'Device Authorization Information'. Does anyone know why I can't read the book on my kobo reader?