Okay -- I have an inconsistent problem and just want to know both why and what I need to do to make it work. I have a Sony Reader PRS-300. I get ePub files through www.mymediamall.net.
The way I've been transferring them: Download through mymediamall. They appear in the Sony Reader software on my computer. Then I open up ADE. Add the items to library. Then I drag them from the ADE library to my Sony Reader (which appears in the ADE menu).
Generally it works all right. But many times (like tonight....grrr!), ADE doesn't unlock the files. I can read them on my computer in ADE (both from the main library and from the PRS-300 library), but when I disconnect the Reader, the files are locked.
I've been getting around it by trial and error, sometimes deleting everything and re-downloading, sometimes just re-adding the files to the ADE library. But it's a real PITA and if I know the why, I can logic through how not to have it happen again. Tonight nothing seems to work to fix it.