Mature contains, stable, but old software that is not maintained. 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!