I have the same problems.
0023 or 1.0
groups | grep "$(ls -l /dev/ttyACM* | awk '{print $4}')" > /dev/null && echo "Permissions correct"
ok
ls -l /dev/ttyACM0
ok
groups --> dialout
When I start-up /dev/ttyACM0 is in the menu.
If I want to upload /dev/ttyACM0 is not found......
It must be in 12.04