It turns out that apparently Adobe has disabled movie playback in newer versions (9.4 and up) of Acrobat Reader in Linux.
Where can I find deb packages of older versions?
The idea is to overwrite the currently installed version (9.5.1) in Ubuntu 12.04. There are some launchpad repositories, with, for example, acroread-9.3.3-1lucid1.deb but the file shows as "(deleted)".