Slim Framework .htaccess / mountain lion osx

I have a problem that has caused me a few headaches and I'm hoping maybe someone on here has some light they can share.

I was previously running OS X Mountain Lion with no issues at all with slim framework. Since upgrading to OS X Mountain Lion, I've had nothing but trouble since it rewrites your httpd.conf and other settings. One of which seems to be htaccess. I have vhosts setup and some previously working using slim are now broken on any url other than /.

So my htaccess file has not changed since upgrading so I'm wondering what the problem is. I'm using the default htaccess as supplied in the slim framework download, I even tried a custom one but to no avail.

Visiting / produces the required page. Visiting a different URL does this:

Not Found

The requested URL /myurl was not found on this server.

Any one any tips?

mod_rewrite is enabled, and this is what my vhost setup is:

<Directory "/Users/chris/Sites/slimphp/">
    Allow From All
    AllowOverride All
</Directory>
<VirtualHost *:80>
    ServerName "slim.php"
    DocumentRoot "/Users/chris/Sites/slimphp"
</VirtualHost>