Hopefully someone can tell me there's a way to do this.
Last year I bought my missus a Sony e-reader for her birthday. We did the registration bit okay and bought four books using my Adobe DRM ID.
At xmas my missus got a netbook. Again we installed the reader software and we bought four books. This time we used my missus DRM ID and re-registered the e-reader.
So my question is - Can I re-register the first four books we bought from my ID to my missus ID?
You'll need to talk to the place where you purchased to books to see if they will let you redownload the books.