Pdf to ePub formatting issue

[PatNY]

In converting a pdf ebook to epub format using Calibre, I noticed that some paragraph breaks as indicated in the pdf file are not being picked up in the output epub file. Most of them are, but in many cases the output file will have 2 paragraphs combined as if they were one.

In the pdf file, all paragraphs are indicated with a one-space indent. Is there any way to force Calibre to treat all such indents as a new paragraph when converting? Also, why is Calibre correctly interpreting most of these indents as paragraph breaks but not all?

Are there any other tweaks to the output settings I should make to produce a better pdf-to-ePub output? Currently I'm using a line un-wrapping factor of 0.7 which is giving good results.