No white enter lines in blog posts

I really love the theme but I ran into a problem wich needs to be resolved to keep using it because everything works fine except when I write a post and hit enter and send it in the text will be just behind each other in stead of on a new line. I tried tinymce with the line break option on but no luck.

I guess there is something wrong in one of the style sheets but I can’t figure out what it is.