How do you deal with the zoo of Opera versions?

Question

Opera

All developers don't like IE6, and for a number of reasons. But, at least, all his glitches have already been described 100,500 times on the net. Yes, and software for testing such as IE Tester for different versions of the donkey was made by craftsmen.
And here's what to do with Opera ...
On one project from Belarus, I now have 41.2% of visitors using the Opera browser. Maybe someone would be happy that the share of IE in the sum of all versions is only 38%, but as practice shows with Opera, there are enough problems of their own. Clients constantly contact me with complaints that they have Opera and: sometimes the order system does not work / sometimes tabs are not opened, etc. And the saddest thing is that I have never been able to reproduce the situation .
According to distribution statistics, different versions of Opera:

It's still a zoo. Plus, every share-significant version needs to be tested in two modes with and without Turbo.
Share your thoughts, who and how tests their products for this whole zoo of versions?

Answer 1

I usually beow the first top three, + client version. It's not very fair, but catching bugs in every 0.0000x version or the next Opera update can drive you crazy. At least until they come up with a universal Opera tester :)

Answer 2

And yet there is a fit to the width of the page, which distorts many sites a lot of fun :)