Bonjour, I have several installation of FC4 with rkhunter on board, I always have this problem with only one machine: Rootkit Hunter 1.2.8 is running Tue, 21 Mar 2006 04:02:05 +0100 Determining OS... Unknown Warning: This operating system is not fully supported! Warning: Cannot find md5_not_known All MD5 checks will be skipped! What does that mean? Every installation on other machines are very similar.... BTW: when you update rkhunter, the new version crush the previous /etc/rkhunter.conf It should be convenient to have a "rpm.save.new" file. Thanks. -- François Patte UFR de mathématiques et informatique Université Paris 5 - Paris http://www.math-info.univ-paris5.fr/~patte