Looks like someone found the reason for this problem in another bug: https://bugs.launchpad.net/ubuntu/+source/hal/+bug/267682/comments/84
"It seems that the X server grabs the relevant /dev/input/eventX with ioctl(EVIOCGRAB), which means it gets exclusive access to the events"
Looks like someone found the reason for this problem in another bug: /bugs.launchpad .net/ubuntu/ +source/ hal/+bug/ 267682/ comments/ 84
https:/
"It seems that the X server grabs the relevant /dev/input/eventX with ioctl(EVIOCGRAB), which means it gets exclusive access to the events"