A column contains a list of dates in the form: day/month/year.
If the list contains all single-cell days, then sorting in descending order works fine. However, if the list contains a date such as 24/4/2005 as opposed to 2/4/2005, the date 24/4/2005 always appears first on the list, above an earlier date such as 1/1/2006!

For example, here is a "sorted" list:

24/2/2005
6/3/2006
3/4/2006
3/4/2006
3/4/2006
3/4/2006
3/4/2006
1/4/2005
8/4/2004

As i said, when there are only single-digit days, the sorting works fine:

6/3/2006
3/4/2006
3/4/2006
3/4/2006
3/4/2006
3/4/2006
1/4/2005
8/4/2004
8/4/2004
8/4/2004
8/4/2004
8/4/2004