Linux with alt and altgr

/usr/share/kbd/keymaps/i386/include/linux-with-alt-and-altgr.inc

Add these two lines to the end of the file:

altgr keycode 16 = slash

altgr keycode 17 = question

Then simply run the command:

loadkeys br-abnt2

Can't Run KDE 4.5.5 in VirtualBox

If X crashes at start, try disabling compositing.
Create a file named /etc/X11/xorg.conf.d/disable-composite.conf with this in it:

Section "Extensions"
Option "Composite" "Disable"
EndSection