SVN getting a “Could not open the requested SVN filesystem” error both in terminal and at the url

Question

I've been trying to get my svn server up and running, but when I try to go to the url, all it displays is

This XML file does not appear to have any style information associated with it. The document tree is shown below.
<D:error xmlns:D="DAV:" xmlns:m="http://apache.org/dav/xmlns" xmlns:C="svn:">
<C:error/>
<m:human-readable errcode="13">Could not open the requested SVN filesystem</m:human-readable>
</D:error>

When I try to call something from the command line "svn ls http://mydns/repos/testsvn" and it says "svn: Could not open the requested SVN filesystem."

and my /etc/httpd/conf.d/subversion.conf contains

LoadModule dav_svn_module     modules/mod_dav_svn.so
LoadModule authz_svn_module   modules/mod_authz_svn.so

<Location /repos>
   DAV svn
   SVNParentPath /var/www/svn
   # Limit write permission to list of valid users.
   AuthType Basic
   AuthName "Authorization Realm"
   AuthUserFile /var/www/svn-auth/passwd
   AuthzSVNAccessFile  /var/www/svn-auth/access
   Require valid-user
</Location>

I've chowned both the svn and svn-auth directories to apache.apache (and tried apache:apache), as well as set the permission bits to 777 for both directories, just to see. Any idea why I'm getting this error?

And I've tried checking around SF.com and SO.com and couldn't find a solution, so I'm asking here now.