I have problem with this function because i work in Maya and other 3D applications that use this key combination... This option on Ubuntu 11.04 was in "window" section so i could change it to something else to avoid conflicts... where is this located in Ubuntu 11.10?
It’s a Compiz plugin.
Install Compiz Config Settings Manager (
Once opened, search for a “Move Window” plugin. Select it, and disable or change the first option, that says something like “Initiate window movement” (I have Spanish locale).
For Unity 2d:
In conf-editor (you can open it from terminal) go to: