How to migrate older books from Adobe Reader to Digital
Editions?

I own a number of Adobe ebooks (bought from amazon) that worked fine on the old
Adobe Reader using DRM activation. I used my microsoft.net passport to activate
the computer.
Now I finally have the new beta version of Digital Editions that is actually
supposed to work on my mac, but it won't open my old ebooks. I had to create a
new Adobe ID, which is of course different from my microsoft.net passport. How
can I consolidate the two IDs? Digital Editions prompted me to re-download my
ebooks, but I haven't found any place on amazon where I could do that.