OK. Finally i got this stupid thing resolved!! For sure WYSINEWYG (What you see is not exactly what you get), or maybe i could say what you don't see is exactly what you get!! :rolleyes:
In dreamweaver and notepad i couldn't see anything weird. Then i had a look at my php file with an editor which is part of the H-Sphere software used by my hosting company, and just before the opening <?php of my index.php i saw some characters that shouldn't be there. As soon as i removed those characters the problem resolved! I had a look at all my files (created with dreamweaver) and those characters are always there, but i can only see them with the specific editor. That really sucks, so for any people that maybe face this problem in the future, just try viewing the files with some other editors as not all of them can display those characters.
Thank you all guys for your help! 🙂