I think I found the root cause, and I believe it is a bug in OX2: The weather tile only works if you set your current location to United States, even if you don't live there.
These are the steps (in Vista):
Control Panel home - > Clock, Language and Region -> Change the country or region -> location
select United States -> ok
Origami Now -> Weather Tile -> Main tile options
Enter the desired location (e.g.: Brussels, Belgium) -> click on the arrow and then select the result of the search
Hit close and you are done.
Unfortunately, until this bug is fixed you must leave your current location set to US -this will not impact other regional settings (time, date and tune formats, number formats ).
Hope this can help.