oocalc problem: Sort by date

Hi all,
I'm fighting with date sort order in my spreadsheet, I'm attaching the file having this issue.

The first column contains date in DD/MM/YY format.
The problem rises when I try to sort the rows by data from the oldest to the newest.

Calc sorts only the day and do not consider the whole date format data.

May you help me, please?

Thanks,
M

Which version of LO?

There was a bug in 4.2.7 which involved sorting
(more info on this in the release-notes:
http://www.libreoffice.org/download/release-notes/ )

Update to 4.2.8
Or update to 4.3.5.2