I also had the youtube comments problem, and this indeed fixed it

Go to "opera:config --> User Prefs" and copy this line: Mozilla/5.0 (Windows NT 5.1; rv:31.0) Gecko/20100101 Firefox/31.0 to the "Custom User-Agent" field. Don't forget to click "Save".

But the problem is, now addblock doesnt work anymore.... it's like you fix one thing and another brokes down, Opera 24 looks totally incomplete, I love opera 12 but it gets harder and harder to keep everything going.

Any idea how i can fix adblock WHILE still be able to see comments on youtube?