[Chris Jones]

Thanks much for all the comments..!

I tried pretty much all the above-recommended methods to no avail.. including Calibre conversions from epub to epub and epub to kepub.. The conversion jobs appeared to be dead in the water — progress bar stuck for something like 40-45 minutes, which didn't sound plausible even for an oversized ebook.. and since it looked as if those conversion jobs were intent on frying my laptop's CPU I decided to play it safe and killed them.

I eventually figured it might be of interest to ask for a second opinion.. so I booted debian unstable and fired up Sigil, pointing it to a copy of the epub. After what felt like ages I saw a popup that basically (can't remember the actual wording..) informed me that the .epub was broken.. but that Sigil was willing to try to fix it at my own risk. Since I had nothing to lose, I did just that and after another fairly long interval.. Sigil was eventually able to display the book. So, I did a "Save As" under a different name.. uploaded this new file to Calibre... proceeded to convert the .epub to a .kepub.. and this time the conversion was successful (mind you, this took about ten minutes.. which is rather surprising on this rather powerful laptop of mine — hey, that's about the time it takes it to build a linux kernel) ...

Finally, I uploaded the book to the Glo' and at long last, I was able to open it.

So it looks like this everything-in-one-file version of Hume's History of England (that suspiciously doesn't seem to be available from PG any longer...) was badly broken in the first place.

Moral of this story from my uneducated perspective is that short of manually rebuilding the epub, if you really have to do something like this (I only went to all this trouble out of curiosity..) your best bet is to use Sigil's built-in epub-fixing routines and hope for the best.

Thanks again for help..!

CJ