"HOSTS file that can be found in C:\WINDOWS\system32\drivers\etc . ... Among other sites there was also a line: 127.0.0.1 ad.doubleclick.net which was the reason why IMDB trailers did not start so I removed this line from HOSTS file and left other intact and now everything is OK."
This suggestion worked for me on a Windows 7 platform. I edited the “ad.doubleclick.net” out of my HOSTS file and now all IMDB videos work for me.
Thanks, AR Com 
I had problems with imdb trailers, with all software up-to-date but jumps in trilers playbacks.
As from Jeff’s post, disabling Adblock Plus (firefox plugin) on imdb.com (only) worked for me.
You may need to refresh the page after disabling, for instant use
I have to correct myself, nothing to do with Adblock, the solution in firefox was just to open trailers in a new tab (instead of direct click on “watch trailer” button)
I can,t play IMDB.vidoes on my phone i save movies on a list
can you please help me with this.
Folks, I’ve come to the conclusion one must do away with these cronies.
www.tmdb.org (the movie db) it’s a better option more sophisticated no more tracking.