Well, Adobe now has released a Beta of the next iteration of Digital Editions which is supposed to overcome the limitations of the existing version. I won't be giving it a try because I don't want to mess up any of my PDF books that have DRM (I don't have many of them and won't be buying any more). But you can learn more about this new Beta version here:
http://labs.adobe.com/technologies/d...tions/install/
And there is a discussion thread here about the new Beta version:
https://www.mobileread.com/forums/showthread.php?t=20540