Since Nautilus 2.26 in Debian, partitions on removable devices are automounted
again, but for LUKS partitions there is a new bug compared to the 2.24 Gnome.
If a medium with a LUKS partition is plugged, the user gets asked for the
password. However if the mount failed, e.g. due to a wrong pass phrase,
then afterwards, the partition is not shown anymore, so there seems no
other way to get second chance to mount that partition other than re-plugging
the device.
(Which is cumbersome, if there are further, already mounted, partitions on
that device.