Hi Jason,
Thank you for the advice, but it did not resolve the problem. Media Player was turned on already but I tried unchecking it and rebooting it as you recommended. I've tried using both the movie item within a questionnaire and an instruction item with background video. The file is an avi clip but I have tried others without any success. I can hear the audio but no image appears. The html item type is also giving me the same problems. Any other advice you might have would be greatly appreciated. Thank you.
S