I use this extension for such cases:
https://addons.opera.com/en/extensions/details/domainuseragent/

The only downside is that you have to figure out what the "user agent" is yourself. I currently have most success with "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.36".