css background-image

[Andrea]

Hi all :)

I'm trying to add to the "date" of my posts a little arrow in the
background.
So I've opened the advanced editor and saved the theme adding this:

.date {
background-image: url(http://nkjoep.altervista.org/blog/
blog_freccia.png);
background-position: 33px 4px;
background-repeat: no-repeat;
font-weight: 300;
}

(You can see that surfing my posterous http://www.stealthefish.com)

So where's the problem?
The problems is that the image isn't showing :)
And I dunno why!

There are limits for background images?