Hi there,
I have discovered some more clues to the problem that might help you work out what is going on!
The first time I run a questionnaire after starting MediaLab the video file doesn't seem to work. However if I cancel out of the questionnaire (by pressing Alt right arrow), and then run the questionnaire again (without exiting MediaLab in between) the videos seems to work thereafter.
BUT if I open MediaLab afresh, and try to run the questionnaire, the video won't play. If I let the questionnaire file run its course (without pressing Alt right arrow), and then play the questionnaire file again, the video still doesn't work.
It seems as though the video will be able to play, but only after I have cancelled out of the questionnaire using Alt right arrow, and this needs to be done WHILE A VIDEO IS PLAYING.
Anyway hopefully this might give a clue to what is going on, but I'm not sure, I have tested out this theory a few times, but it is also possible that playback is working randomly and I am just seeing patterns when there aren't really any!
Also - another way to get the video to show up once it has started but the screen is black is to put another program window (ie internet browser) over the top of the MediaLab screen, and then take the other window away again. THis can only be done if Medialab is being played in a small screen (for my experiment I would prefer to have the MediaLab window at full size).
Can you make any sense of all this?? Thanks.