How to add property changes on directory to Subversion

I am having trouble adding property changes to a directory on a changelist using the Subversion commandline client. Subversion keeps skipping the directory I want to add (which is the trunk of my project). See the console output below, from the root of the working copy. The changes I want to add are on the . directory.

$ svn st
 M      .
M       some/file/do-not-commit.html

--- Changelist 'index':
M       some/other/file.html

Here's the diff:

$ svn diff
Property changes on: .
_______________________________开发者_如何学运维____________________________________
Modified: svn:mergeinfo
   Merged /extern/trunk/site:r135-162

<snipped rest of diff>

And what happens when I try to add the property changes on . to the index changelist:

$ svn cl index .
Skipped '.'

Can someome help me beat Subversion into submission? Thanks in advance. For completeness, here's the exact Subversion version (it's the one from Debian Squeeze):

$ svn --version
svn, version 1.6.12 (r955767)
   compiled Mar  1 2011, 22:17:06

Copyright (C) 2000-2009 CollabNet.
Subversion is open source software, see http://subversion.tigris.org/
This product includes software developed by CollabNet (http://www.Collab.Net/).

The following repository access (RA) modules are available:

* ra_neon : Module for accessing a repository via WebDAV protocol using Neon.
  - handles 'http' scheme
  - handles 'https' scheme
* ra_svn : Module for accessing a repository using the svn network protocol.
  - with Cyrus SASL authentication
  - handles 'svn' scheme
* ra_local : Module for accessing a repository on local disk.
  - handles 'file' scheme
* ra_serf : Module for accessing a repository via WebDAV protocol using serf.
  - handles 'http' scheme
  - handles 'https' scheme

The changelist in Subversion does not support property changes. Only files nor directories.