Links not displaying in post when I just the text editor link button

Hi,

When I try to add links to my posts or pages with the wordpress link button in the text editor field, no links appear in the post page.

When I add links manually with some different code the links appear though, so it doesn’t appear that something prevents links from being visible in general.

Example:

At the bottom of this post:
http://www.nutritiontactics.com/more-reps-more-muscle-mass/

I entered a link to the source. Both by the wordpress link button feature and by manual code. Only the manual code is showing (see the lack of a link after the first ”Study”).

Here are codes:

Study:
Study: PLoS One. 2010 Aug 9;5(8):e12033.

Big Thanks in Advance!
Jorn