<alt> and left mouse button

[Johan Meskens CS3 jmcs3]

hi

i cite:

"
The problem isn't with Blender at all. It's just that your desktop 
manager currently "owns" that combination. In many desktop managers 
(KDE, Gnome, Fluxbox, etc.) in Linux the LMB Alt combo is used for 
moving windows around. It's a feature not a bug.  Unfortunatly, Blender 
(and other complex 3D packages like Maya, XSI) need this combination for 
all kinds of things.

To fix it you need to either disable the function or rebind the 
combination to a different key (windows key works) in the desktop manager.
"

how can this be done/fixed in ubuntu ?

thanks
jmcs3