On my system after upgrade from 13.04 to 13.10 and then to 14.04, custom shortcuts didn't work because the wrong keysyms were being generated, according to xev, despite my use of xmodmap in .xsession called by nodm. I fixed it by delaying the xmodmap by two seconds. I speculate that the X server initialisation of keyboard mapping changed in a way to introduce a race condition, and so setting the keyboard mapping later worked around the race.
On my system after upgrade from 13.04 to 13.10 and then to 14.04, custom shortcuts didn't work because the wrong keysyms were being generated, according to xev, despite my use of xmodmap in .xsession called by nodm. I fixed it by delaying the xmodmap by two seconds. I speculate that the X server initialisation of keyboard mapping changed in a way to introduce a race condition, and so setting the keyboard mapping later worked around the race.