You're going to want to actually view the source of the page and search for the text there -- otherwise it's possible that it's being hidden by the CSS so it won't come up in a search of the page itself (but it would show up in the "view source" or "page source" or whatever it's called in your browser).

That being said, it's unlikely that this is the problem. I just looked at your typography.css file and noticed that you have some customization comments (e.g. "/* customize_p */") around some things that it doesn't work with -- for example, you have it around a margin-bottom in the "p" section, and around text-decoration in the "a" section. Unfortunately, Concrete5 only provides support for color and font -- not any other styles. So this might be causing the problem as well. Try removing all of those comments from the typography.css file and see if that helps.

Another thing to try is when you're in the WYSIWYG editor for the content block, click the little "HTML" button in the toolbar and see what source it's generating for the one that's not working. Perhaps it is something weird or something that's getting overridden somehow?

A third thing to try is just publish taht page and see if the content appears. I sometimes have problems with content not appearing properly when I first add it to a page, but when I publish the page (or even preview it), it looks fine.

Hope this helps.