In case someone else gets the same problem: - open GRUB: sudo gedit /boot/grub/menu.lst - scroll to the bottom, where the different boot options / kernels are shown - disable kernel 2.6.24-24-rt (as shown below) #title Ubuntu 8.04.2, kernel 2.6.24-24-rt #root (hd0,0) #kernel /boot/vmlinuz-2.6.24-24-rt root=UUID=69b147aa-3f47-4521-a71f-3249309416e0 ro quiet splash #initrd /boot/initrd.img-2.6.24-24-rt #quiet #title Ubuntu 8.04.2, kernel 2.6.24-24-rt (recovery mode) #root (hd0,0) #kernel /boot/vmlinuz-2.6.24-24-rt root=UUID=69b147aa-3f47-4521-a71f-3249309416e0 ro single #initrd /boot/initrd.img-2.6.24-24-rt -reboot VM <div class="gmail_quote">On Fri, Apr 10, 2009 at 12:16 AM, Viktor Mastoridis <<a href="mailto:viktor@mastoridis.co.uk">viktor@mastoridis.co.uk</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Hi, I've been using UbuntuStudio 8.04 (64bit) happily for a year now, really solid and stable... Today, came from a short holiday and installed the upgrades that were due. A casual process, never had problems. After the upgrade - jack would not start, the RME HDSP 9632 card had disappeared (Sound Preferences says: Not Connected; jack doesn't show it in the Setup...) Here's a log of today's upgrade: <a href="http://mastoridis.org/upgrade.txt" target="_blank">http://mastoridis.org/upgrade.txt</a> Here are jack's messages: <a href="http://mastoridis.org/jack.txt" target="_blank">http://mastoridis.org/jack.txt</a> system Monitor reads: Kernel Linux 2.6.24-24-rt Did the (Linux Audio) World change in 7 days? Am I missing something? Help/explanation will be thankfully accepted. Viktor Mastoridis </blockquote></div>