Windows Movie Maker preview screen does not play

my windows movie maker 6.0, preview screen does not play in timeline or
storyboard mode. It plays 1 of my two movies ive made but it wont play the
other one. It was working fine and then all of a sudden it just stopped
working. It shows all my pics and video clips in the timeline but it just
wont play when i push play. Can someone please let me know how to fix this
problem.

[aussie ewok]

I have also spent many frustrating hours trying to fix movie maker. The audio and video seem to be on the timeline and they worked earlier in the morning but suddenly the preview only played audio. There are lots of people trying to delete and reinstall movie maker but the problem is most people have movie maker bundled in XP service pack 2 and therefore do not have a disk (since they downloaded from the internet). What finally worked for me was to simply uninstall internet explorer 7. When you do this it automatically reverts back to ie6. As soon as ie7 was removed I had my video back! Hope this helps.