I've tested how an upgrade from CentOS 5.2 to SL 5.3RC2 would go. For this, I setup a CentOS 5.2 system with Apache active. I downloaded the sl-release-5.3-1.i386.rpm and yum-conf-53-1.SL.noarch.rpm files. When I tried "rpm -Uvh *" I got the following error: "file /etc/yum.conf from install of yum-conf-53-1.SL conflicts with file from package yum-3.2.8-9.el5.centos.2.1". To solve this, I used the additional "--force" to install both files. Since there is an issue with glibc (important! see RHEL release notes, more info here: http://www.pendre.co.uk/screen.php), I updated glibc first and used "yum update" to do the rest. That went without a problem. In the end, there were 8 new packages to be installed, 207 to be updated and 0 to be erased. Total download was 356MB in size. After the update, I rebooted and then several strange things started to appear: *Grub* The splash image of Grub still was the one from CentOS (no update to the one from SL). *GDM* When GDM started, there was a problem with the theme: "There is an error with the EaseOfBlue theme, can't open file /usr/share/gdm/themes/EaseOfBlue/EaseOfBlue.xml". Apparently, there is only one theme in /usr/share/gdm/themes and it's not the right one. It skipped to an very basic login. *Gnome panel* After the login, the icon used on the Gnome application panel still was the one from CentOS. Regards, Patrick