I started a discussion on a problem I was having with my laptop running too hot
(
http://supergamer.org/vl/forum/index.php?topic=6658.msg45548#msg45548 ). I noticed that the laptop's temperature went up a lot when Opera was running, but not when SeaMonkey was running. Modprobing powernow-k8 and setting vcpufreq to ondemand made a substantial improvement in the heating problem. However, Opera still had a tendency to raise the temperature when it was running. (I used System Profiler and Benchmark to track the temperature, but I have some doubts about how reliable it is, especially on a laptop.)
In checking htop, I noticed some operapluginwrapper processes and decided to terminate them to see what would happen. Lo and behold, the computer cooled down and nothing seemed amiss with Opera. Flash is working. I also got rid of the operaplugincleaner process with no apparent ill effects. So now I make sure those operaplugin things aren't running, and things aren't heating up the way they do when they're running.
I don't have this problem on my Athlon desktop. The laptop is an all-NVidia system. I don't know whether any of that is involved.
If any of you are having problems with Opera hogging CPU cycles or making your computer run hot, please see if killing the operapluginwrapper processes helps out. And be sure to report your results.
I'm running Opera 9.51.
--GrannyGeek