Exporting to .mov

I need to export my flash movies to .mov files. When I do that it says Quicktime doesn’t support it above Flash 5. So I change the settings and try again. It exports successfully. When I play the movie on my computer it plays the right way. When I transfer it over to my proffessor’s computer It plays as a sound file. The size of the file on my computer is only about 6kb for a 200+ frame animation.

Can anyone help?
BTW I’m using Flash professional 8 and Quicktime 7.1.3 Pro