I had a similar issue, the text before the more tag was being displayed on the main post listings page, but no "continue reading" link, and you would have to click on the title to get to the single post and read all the details.
If this is the case for you, it’s a very simple fix:
login to your admin page and goto Appearance > Customise. In the Customise menu that appears on the left hand side, click on Archive Pages. Make sure that "Show Post Excerpt" is not checked
