[cluelass]

I was having the same problem as Papa John after exporting a document from Pages to epub, and then converting to Calibre. The epub looks perfectly fine in an epub reader, but after conversion to mobi, the Kindle breaks lines in the middle of words.

Turns out there is a style command inserted by Pages that in effect tells the reader app to treat the text as pre-formatted with regard to line breaks. This command gets passed through Calibre to the mobi version, even if you "clean up" the epub by doing an epub-to-epub conversion. Kindle sees each paragraph as one long line, and since there is not enough room to put it all in one line on the Kindle display, it just breaks the line whenever it runs out of space.

Here's the solution that worked for me: When you open the epub for conversion in Calibre, go to the "Search & Replace" tab. Enter the following in one of the "Search Regular Expression" lines, with no replacement text:

[ style="white-space:pre-wrap"]

No brackets. Otherwise use exactly as written including the quote marks.

Then convert as usual. When you upload this mobi file to Kindle, you should see normal line breaks between words. Let us know if it works.

Cheers,
Kate