I have no idea what can be wrong here. Can you try to run this
command as root and submit the output to us?
/usr/share/bug/discover-data 3>&1
discover --disable=serial,parallel,usb,ide,scsi \
--format="%V %M\t%S\t%D\n" video
It might give me a clue about the source of this problem.
Friendly,
--
Petter Reinholdtsen