Stable contains the latest stable version considered ready for
production servers.

The source file (.source.tar.gz) is always the most up-to-date.
Sometimes it takes a few days for the package maintainers to get round
to producing  the .deb/.rpm/.pkg files.

Be aware that only the RH6.2 and RH7.0 RPMs are made by the
DansGuardian author and all others are contributed.

The best thing is to grab the latest stable source and compile from
that.  It's easy, trust me!