I don't know if anyone else has run into this or not. I have a large library of MobiPocket ebooks. Recently I also downloaded Amazon's "Kindle for PC" app, since some books simply are not available as MobiPocket ebooks. Having done this, I noticed that all of the .prc MobiPocket ebooks in the My eBooks directory would try, and fail, to open in Kindle for PC, not in Mobipocket Reader. I went into the My eBooks directory, selected one file, and right-clicked into Properties then changed the format FROM Kindle TO ebook. This converted all the other files in the directory back to ebook, and after this, all would once again open in MobiPocket Reader. Just posting this in case anyone else gets hit with this issue
