I have found a workaround (Because Ubuntu12.04 still doesn't have the fix commited for now) .
You must use the keyboard and the mouse.
I you want to maximize on left screen:
1. Drag your window in the left monitor, with your mouse (normal size)
2. CTRL + SUPER + left arrow
3. CTRL + SUPER + up arrow
I you want to maximize on right screen:
1. Drag your window in the right monitor, with your mouse (normal size)
2. CTRL + SUPER + right arrow
3. CTRL + SUPER + up arrow
I have found a workaround (Because Ubuntu12.04 still doesn't have the fix commited for now) .
You must use the keyboard and the mouse.
I you want to maximize on left screen:
1. Drag your window in the left monitor, with your mouse (normal size)
2. CTRL + SUPER + left arrow
3. CTRL + SUPER + up arrow
I you want to maximize on right screen:
1. Drag your window in the right monitor, with your mouse (normal size)
2. CTRL + SUPER + right arrow
3. CTRL + SUPER + up arrow