HTML tags not being rendered

HTML tags not being rendered

I'm building a simple blog system with FuelPHP and TinyMCE editor.
When I format my text in the TinyMCE (or CKEditor, doesn't matter) and
save it in my database everything is OK. However when I print the text
back, surprisingly, my browser won't render the html tags and displays
them as plain text!
I have checked and I don't have any kind of CDATA in the page, that might
cause the issue.
Here is how it renders:

However, when inspecting the issue with FireBug, I noticed a lot of spaces
before the <h2> tag is being printed! If I just make a small change in the
spaces (Remove one or add another), then the browser will render the tags
and display the text properly!!
Can you guys help me with this issue? It's really weird.