By default the key-mouse combination activates the window menu.
The "activate the window menu" shortcut is currently set to "alt+space."
The Alt-RMB key combo is used in blender for selecting edge loops.
Install the compizconfig-settings-manager package and run ccsm. At
P.S. If this doesn't work, assign a different key to
Fix Alt-drag window move:
With Unity-2D (and now Gnome 3), this is controlled using the
To re-enable it, run:
Note that this GConf key controls several mouse shortcuts:
Alt-drag fix for gnome 3:
If that doesn't work, try this:
Why this should be necessary when there's a dialogue for system hotkeys under keyboard preferences, is beyond me. Very frustrating having to hunt it down with each new release/update of gnome!
Try shift + alt + RMB. That was the best solution I could find. You can customized your keys in Blender's user preferences to change loop selection to something else too.