One other question: Is the "Calibre" program, when it starts up, loading up your main ebook collection by default?

If it is, can you make it so that it doesn't do that, so that you can separate out the two possible steps?

- Clean loading of Calibre
- Loading up your particular eBook file

If you can get it to just do the first thing, if that thing is what's taking 55 seconds... yeah the caching thing is a red herring.

If it's the loading of the eBook file that takes 55 seconds, then that's a different question. There could be something weird in the file, like a circular database reference or something.