In frustration I put this whole business aside for a few days. The break inspired me to fresh thinking about the problem. The epub books I was having a problem with I had downloaded some time ago onto my previous computer. When I bought my new computer I just copied the files over. So anyway I deleted these old files and then downloaded them once more from my Sony ebook store account. Problem solved. The procedure worked perfectly to strip the DRM. Thanks so much for your help. Now if I could just
remove the DRM from a couple of books I have in PDF format.
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