Logged In: NO

I've got the same problem. Without --posix it seems to work
again.
Found in the tar manual :
The version 1.14 of GNU tar is able to read and create
archives conforming to POSIX.1-2001 standard.

A POSIX conformant archive will be created if tar was given
--format=posix option. Notice, that currently GNU extensions
are not allowed with this format. Following is the list of
options that cannot be used with --format=posix:

* --label=archive-label (-V archive-label), when used
with --create (-c).
* --incremental (-G)
* --multi-volume (-M)

This restriction will disappear in the future versions.

So may be the solution is to wait a little...