Piwik cannot detect Opera?

Hi, guys.
I setup the installation of Piwik. Everything works excellent. Only one problem is there: Piwik cannot detect Opera browser clients. Please, help me to fix that.

Thanks in advance.

Opera use similar user-agent of Chrome as you can see here:

User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.154 Safari/537.36 OPR/20.0.1387.91

because the newer version use WebKit.
Anyway piwik must implement Opera detection because OPR/20.0.1387.91 mean that is opera and the version of it

Which version of PIWIK are you using?
There was a problem, but it should be fixed(Opera detection is working fine on demo.piwik.org)

I am using Piwik that is downloadable from piwik.org.

Can you please try with 2.2 from: 301 Moved Permanently