What would cause a 404 error for a file that definitely exists?

What would cause a 404 error for a file that definitely exists?

I just moved a Wordpress installation to a new server. Everything works
aside from all the content in the wp-content/themes directory. All the
images/css/js files contained in my themese are returning 404 errors but
the files are definitely there.
I have checked file ownership and permissions (both OK) and deleted my
.htaccess just in case but it still wont work.
I just moved a VBulletin forum in the process too and that works
perfectly. The issue is strictly with my Wordpress theme dir.
The site is http://www.hachiroku.com.au
A CSS file for example,
http://www.hachiroku.com.au/wp-content/themes/hachiroku2/style.css returns
a 404.
Thanks for your help!