The link for "Remember-Me chapter" at http://static.springsource.org/spring-security/site/docs/3.0.x/reference/ns-config.html#ns-remember-me does not point to the Remember-Me Chapter
This appears to be a problem with all cross-references at the moment. Not sure why it's stopped working, but I'll probably update all the doc processing stuff to use Docbook 5.
Should be fixed now. Thanks for pointing it out.