I don't know why, but for some reason middle-clicking on a link does nothing on your page (instead of opening the URL on a new tab). I'm using Firefox.
EDIT: The problem doesn't occur if I disable Javascript.
It only appears to impact the blog post. If I go to your home page, middle clicking works as expected.
Also, I'm getting a character encoding glitch that's rendering gibberish next to your login button.
One last thing: it also looks like Tumblr is adding stuff to the top of your HTML. On the blog, I see two doctype declarations; one's on the first line, and one's at the very end of the second line.