I'm having some trouble aligning a main image. It should be center-aligned horizontally, yet keeps going all over the place. The page can be found here <http://0034.eu/propmanager/>

```
<img src="images/background-space.png" class="displayed" border="0" />

IMG.displayed{
    display: inline-block;
    margin-left: auto;
    margin-right: auto;
}

```

That's basically the CSS I have applied to the image, all the source code is on main index.html (no separate style sheet).