As of 01/24/2014, all QuickBooks Online REST API v2 requests are now prevented from connecting to NON US QuickBooks Online companies. You can read more about this restriction in this 12/12/2013 blog post.
If you are still using a v2 request, you will receive the following response:
403 – Forbidden: You don’t have permission to access this URL
Here are some useful links if you need to migrate your v2 requests to v3:
Known QuickBooks Online REST API v3 migration issues
QuickBooks Online REST API v3 migration FAQ
Forum: Migrate QB Online REST API v2 to QB Online REST API v3
Ticket: Request specific migration support