When I export a 'photo story' in .avi, seemingly everything is fine. When I try to play the movie in Windows Media Player 11, however, nothing appears on the screen.
In other words, Windows Media Player seems to be playing the movie but it is not.
As a test, render a couple of seconds as a tga sequence, to make sure your project is fine. If that's fine, maybe try rendering to wmv, or try quicktime:animation. What codec were you rendering to? I rarely use avi, unless maybe I render xvid, but that's maybe once a year.