Zoetrope

Here's how to get your Focusrite LiquidMix running again if you're on a Mac OS X Tiger install that was upgraded to Leopard:

Create textfile /private/etc/sysctl.conf and reboot:

kern.sysv.shmmax=536870912
kern.sysv.shmmin=1
kern.sysv.shmmni=128
kern.sysv.shmseg=128
kern.sysv.shmall=131072

My Focusrite would only work on a virgin Leopard install, now it works without a problem on my Tiger→Leopard upgrades too. Courtesy of a very quick support email to Focusrite.