I talked to a person today on twitter who spoke Dutch. I helped him with a problem with the formatting of texts in posts. I have had this problem several times also.
If you are posting in the visual editor. Which I believe most of us do and you start having a problem with the formatting switch to the HTML view. Go ahead don’t be afraid. You may see in there HTML tags that may have been added. HTML tags are things that look like <h2> … </h2> or <span>…</span> There are usually opening and closing.
Many times if you just switch back to the “visual editing” it will clear some of the editing. If it doesn’t fix the problem get back into the HTML and snoop around a little to see if there may be something weird going on. If you want to learn a little more about HTML tags go to W3Schools.com
good luck
PS
Thanks to Thomas Van Oppens for bringing this up.
Take a look at @ThomasVO on twitter. and his cool perspective @ his wordpress blog in Dutch. English with a little google translate magic