Hi!
I'm not stripping DRM at the moment (though I am considering it), but I have previously added DRM'd books to my e-reader via Calibre without these problems. The
Calibre FAQ says that as long as your device is authorised and you extract the ASCM file with ADE it should work, and it did previously - I'm not sure why it isn't now.
The book transfers and opens on the e-reader okay (which it didn't when I tried to transfer them without authorising my device) but everything is blank.