Thank you DiapDealer.
Good suggestion but the problem was elsewhere. I went into Sigil and looked at the html and found seperations the code between the words where they split into new paragraphs. I just deleted them and will now check to see if they are the problem. I suspect they are but how they got there is a mystery. I stripped the text back to Times New Roman but I guess I had some formatting left that cause the problem. I assume that the problem is in my epub html and not in its translation to mobi.