More problems with locales and dates

[Chris Seaton <chris chrisseaton com>]

My locale is set to en_GB.UTF-8 (I checked using 'locale').

In one sheet I have dates such as

6/10/2005

Which is the 6th day of the 10th month of 2005, or October 6th, 2005. I 
went to format cells and chose the mmmm-dd-yyyy format and it comes up with

Jun-11-2005

Where's the problem and how do I fix it?

Thanks

Chris Seaton