I hope you get an answer I have the same problem with XP
I have seen a few issues with ADE 2.0 and reverted to the earlier 1.7.2.
I don't know if ADE2.0 has issues with XP, but it is worth trying 1.7.2 and seeing if it is any better for you..
Version 1.7.2 is a little difficult to find,
I found it for PC at http://www.tucows.com/preview/853736/Adobe-Digital-Edition-For-EBooks
Give yourself a medal, sjpt - I'm sorted now!
Thank-YOU. I WAS LOOKING FOR THAT ALL DAY. I HAD IT ON BEFORE I DOWNLOADED 2.0. Just downloaded and I am back to in I business.