I got a very weird problem. My developer laptop runs Ubuntu 11.04 with Unity. As a Java developer I'm using eclipse which whose shortcuts conflicts with the shortcuts of Unity.
The problem shortcuts is the one for the Spread mode. It is set to Super + W (in my case Windows + W) what is ok for me so far. The real problem is that Spread mode is also triggered when pressing Shift + Alt + Up. Unfortunately this shortcut is already used by eclipse but is somehow overwritten by Unity.
I've already read a lot about how to disable and change the shortcuts for unity using the CompizConfig Settings Manager. But I couldn't manage to disable the Shift + Alt + Up combo.