Even with the password-stores line set in the .subversion/config (password-stores = gnome-keyring), subversion does not save the passwords into the running gnome-keyring-daemon. Brian Dube (http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=553312#55) posted on a separate bug that he was experiencing the same issue. Perhaps subversion is not being compiled for amd64 with the --with-gnome-keyring parameter?

Instead, you get the following:

username@server:~/my_application/trunk$ svn update
Authentication realm: <https://example.com:443> Kerberos Login
Password for 'username':
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ATTENTION!  Your password for authentication realm:

   <https://example.com:443> Kerberos Login

can only be stored to disk unencrypted!  You are advised to configure
your system so that Subversion can store passwords encrypted, if
possible.  See the documentation for details.

You can avoid future appearances of this warning by setting the value
of the 'store-plaintext-passwords' option to either 'yes' or 'no' in
'/home/username/.subversion/servers'.
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Thank you in advance for any help you can provide.