This bug is a part of the issues described on https://bugzilla.ubuntu.com/12598

"When the program starts it displays the most recent entries from syslog;
i.e. the entries from now, today, 11 July.  When I select mail.log it displays
entries from 5 July.  It would be preferable if every view had the same default,
viz., that of showing the most recent entries
...
> it works fine here, all the logs have the current entry selected. What locale
do you use
...
Checking again, I see that 12 July _is_ displayed in the right pane. However, 5
July is highlighted in the calendar at the bottom left. This is what led me to
believe that I was looking at entries from
5 July."