My thanks to elcreative! As he suggested, it is indeed possible to just save the text layer. I initially had dismissed this possibility, because Acrobat X obviously doesn’t offer it (http://forums.adobe.com/thread/546374?tstart=0
). But Abbyy Finereader does. I had overlooked it, even though it figures plainly and squarely in the options of the “save as” menu.
As for the export of annotations, highlights and bookmarks, I have found out that it is possible to save documents with all the notes on your computer using Adobe Digital Editions. And yet this again is a dead end. From there no handing over to Acrobat X, and no printing as PDF file. You are stuck with ADE, which is for my needs far from comfortable (i.e. no highlighting, no copy and paste). Even less so then Sony’s Reader Library. But at least, with ADE, it is possible to create a backup copy on the desktop. A good thing, since I once had to erase all the files of my Sony PRS-650, and though saving the XML files, I wasn’t able to reconstitute the lost documents with my notes.
I now have a rather new question regarding page numbers of pdf files.
When I export my notes via Sony’s Reader Library I have to rely on the correct page numbers. This is rather important for citation purposes. Yet the Sony PRS-650 does not take into account the page numbers I assign to my documents using Acrobat X. Thus, an article on the reader would not start with the correct page 272, but with page 1. As a result, the page numbers appearing in the exported notes differ quite a lot from those in the original article. In contrast to Sony’s Reader Library, Adobe Digital Editions does, however, show the correct page numbers as well as all the notes I have taken. But to my great disappointment it wouldn’t allow me to export them.
The only solution seems to be to fill in blank pages with Acrobat X, to be exact: 271 of them. Or is there any other remedy you could think of?