The filter suffusion_set_more_link wraps the Read More text in a div. This works fine if <!--more--> is on a line by itself, but if it's in the middle of a paragraph, the result is that wpautop "forgets" to close the <p> tag for that paragraph. i.e. given the content:
This is a paragraph. Wanna read the rest? <!--more--> Well here it is!
Wordpress will generate:
<p>This is a paragraph. Wanna read the rest?
<div class='more-link fix'> <a href="..." class="more-link">Continue reading »</a></div>
Thus the <p> tag isn't closed, and validation breaks.
