I'm using the latest version of WordPress (3.7.1) and also the latest version of YOAST WordPress SEO and I have the most common problem with the Arras Project AR2 theme and duplicate titles and meta information.
Here's the theme demo: http://demo.arrastheme.com/
And here's what's happen (screenshot):
As you can see, there's the site name placed just after the post title without any space and there's a duplicate title and description.
Any help will be appreciated!