I noticed this the other day: the Maestro mixer on my Mac was showing the 'From Software' channel clipping. It happened to be that Radium was playing internet radio and the volume slider on the Radium app was maxed. The sliders on the 'From Software' channel in Maestro were set to 0dB.
How can it be that an internal audio signal, completely digital, can clip a channel like this? Even dropping the sliders down on the channel didn't stop the clipping. I had to reduce the volume via the volume slider in the Radium application. That's got me scratching my head a bit and wondering if the app is really clipping it's audio line or if it's the Maestro mixer's channel strip monitors showing me something that isn't actually happening. I couldn't hear any discernable digital clipping on my monitors.
Here's a picture of it occurring...