Google’s algorithm seems to have some holes in it. You can manipulate Google localised search. For example, a website in Google.fr can be damaged by pointing lots of .com/.co.uk links at it. Google will then think the site is not french, lower its search positions and place a [Translate This Page] next to the listing result. The only way to counter this is to obtain more local links which can be much harder than .com links.

Enjoy.