Great, seems we are homing in to the real problem. With the rules disabled, please boot. Now do
sudo strace -vv -s 1024 -f -o /tmp/cdrom_id.trace /lib/udev/cdrom_id --debug --export /dev/sda
and copy&paste the output here and attach /var/log/kern.log and /tmp/cdrom_id.trace.
Is mounting broken now? I. e. does above command trigger the problem for you?
Great, seems we are homing in to the real problem. With the rules disabled, please boot. Now do
sudo strace -vv -s 1024 -f -o /tmp/cdrom_id.trace /lib/udev/cdrom_id --debug --export /dev/sda
and copy&paste the output here and attach /var/log/kern.log and /tmp/cdrom_ id.trace.
Is mounting broken now? I. e. does above command trigger the problem for you?