I installed Luxology modo 701 on my Ubuntu 13.04 but if I try to navigate the 3D via the usual key combinations ALT +Left/Middle/Right Click and Drag nothing happens in the viewport.

ALT +Right Click only gives me Ubuntu's Minimize/Unmaximize/Move/Resize/Always On Top/Close menu and ALT +Left Click and Drag unmaximises the window and drags it around.

So I assume I need to somehow get Ubuntu to not override modo's shortcuts.

Any idea how I do that? Thanks in advance for any help!