I added $USER to group video and created a rule 51-kinect.rules in etc/udev/rules.d as specified in freenect wiki.
freenect-glview and NiViewer ran with no issue. UserViewer ran with terminal displayed the following then it terminated.
OpenNI2-FreenectDriver: Using libfreenect v0.5.2
OpenNI2-FreenectDriver: Found device freenect://0
OpenNI2-FreenectDriver: Opening device freenect://0
[Stream 70] Negotiated packet size 1920
write_register: 0x0105 <= 0x00
write_register: 0x0006 <= 0x00
write_register: 0x0012 <= 0x03
write_register: 0x0013 <= 0x01
write_register: 0x0014 <= 0x1e
write_register: 0x0006 <= 0x02
write_register: 0x0017 <= 0x00
I tried lubuntu 14.04.2 and ubuntu 14.04.2, same results.