Media library upload not possible in multisite

Hi Guys,

I've got a problem regarding the media library on multisites, and I'm completely stuck.

I've got a site which I'm using as multisite, but in any of the new subdomains the media library isn't working correctly.

When I try to upload an image in the media library the image isn't showing (see screen grab), the media library link is shown as : but the image is really at :

In the multisite settings I've got the following settings (I've not changed these from standard). But the url show in the media library isn't finding the image.

Upload path : wp-content/blogs.dir/2/files

Upload url path :

Fileupload URL :

I'm obviously unable to move forward in any way with building this subdomain, as I can't get past this.

I've turned off all the plugins, and have only the Twenty Eleven theme live to try and sort this, please help as I can't find out how to move forward.

Please help!