Hi, Most of yesterday I spent time installing SL.40.042005.i386 onto a couple of my rack systems. One of them uses a Hyperthreading CPU which I've used under HT mode without issues under SL3. However SL40 (aka the vendors newer kernel) has major issues running in HT mode (UP mode works fine), and just has a hard lock-up during the boot process, where the only thing that can be done is to press the power off button. I've tracked this down to a bugzilla filed for FC3: https://bugzilla.redhat.com/bugzilla-old/show_bug.cgi?id=146921 where I get _exactly_ the same issue this guy reported. I disable the various services where the hard lock-up occurs, and it gets past them but then on the login prompt, after entering the username and password the prompt just sits there and you can't login. After alot of trouble-shooting on this problem, I tracked it down to the ACPI support, once I put in: acpi=off into the kernel grub command line, the system booted and runs fine in HT mode. From that bugzilla report, it doesn't look like anything has been fixed with that bug yet. On a side note, I also experienced that "kernel openafs anaconda" problem when burning those ISO's above and installing them onto my rack servers (the error reported by another guy earlier in this list). The way I got round that problem was to do a vanilla "server" install on selection menu (without specifying the packages I wanted and didn't want), and SL40 installed, I then went back into the packages and selected/deselected what I wanted. Do I need to download the new ISO's (042505) and re-install these newly built machines with these ISO's? or is the ISO set I have fine? Michael.