Hi,

I decided to upgrade from Slackware64 13.0 to 13.1 using slackpkg.
I did a slackpkg install-new and afterwards, upgrade-all.

My first problem was solved regarding libblkid.
The second one, with DIALUPS_CHECK_ENB and NOLOGIN_STR was solved too.

Now, when booting, the system says it can't find /sbin/mount, swapon, hwlock and fsck, and also /proc/filesystems and /proc/ioports.
It asks for the root password for maintenance and boots again afterwards.

Do you have any idea what should I look for, because the mentioned /sbin/_files _ are at /sbin ?

You got caught by the libata switchover. See the changes and hints file for a full explanation. You need to change fstab from hd* to sd* entries.