Thanks for the replies.
joshl I have Opera 31.0.1889.174 also installed and have done for over a year now but I prefer 12.17. It plays the IMDB trailers just fine.
nimulan I can't find Settings > Websites but I did un check Preferences > Content "enable plug-ins" if that's what you meant? It didn't make any difference though, the IMDB trailers still don't play. If there's something else you meant or I should try please let me know.