Using Google Webmaster tools my site is set to 'Display URLs as www.mydomain.com' as opposed 'mydomain.com'. This is the setting for both of these sites in Webmaster tools and has been for several months now.
Google has honoured this, but recently the site's ranking has started to improve and it is ranking for search terms it didn't previously rank for.
However, Google is not displaying these new results using my preferred domain (without the www).
Does anyone else have experience with this behaviour? Why would Google do this?