For Barriorsquare on N900, you might stumbled with this error "Error: foursquare.com timestamp refused. Check system clock?" when you try to sign-in to you Foursquare account.
Reason - This is due to foursquare.com requiring all requests to have a timestamp in them, and that timestamp must be within 10 minutes of foursquare's server time. This error means that the timestamp that was sent with your request is out of this range. Check that your device's time is set as close to a reliable source as possible and try again.
So try to reset you clock in setting menu.
