Fixing Emacs ctrl-space (set mark) on Ubuntu 14.04 Trusty Tahr

The Emacs ctrl-space stopped working for me.  I'm not sure if it was related to my upgrade to Ubuntu 14.04 or if it was related to my switching from Unity to LXDE.   I fixed the problem by running ibus-setup from the command line, then changing the default keymap for input method.  The main problem is that the Intelligent Input Bus or ibus, takes over the keymap for ctrl-space.

I've found LXDE to be faster than Unity on my Lenovo laptop with 4 GB of RAM and a Celeron processor.

I've had some problems with Xfce in the past, primarily related to the HDMI port coming out of sleep mode.