I too had this problem except that my clip goes white instead. I have
read all of Sonia's recommendation in the website below and tried
everything mentioned, and I mean everything, but am still unable to
resolve the issue. My problem is even worse as the video clips played
all right in mplay32.exe; they just refuse to play in ppt 2003.
HOWEVER, I am pleased to let you know that after I use the "Package for
CD" function in PPT 2003, I am able to overcome the problem. It's
really funny because the video files in the CD (or folder if you chose
to package to a folder) now plays properly in the ppt while the
original one it came from does not.
I'm not sure what the "package for CD" function did because even after
I deleted all the extra files (the .dll, ppviewer, autorun etc) in the
CD / folder, leaving only the main ppt and video files, the videos
still worked.
What's even more weird is that when I then insert the original videos
side by side with the 'packaged' videos in a new ppt file, only the
'packaged' videos played even though both video files are exactly the
same.
I begining to wonder if PPT 2003 is really cranky/buggy as I have other
complains about it compared to PPT 2000 or PPT xp.
hope this helps you in some way. If you are not using ppt 2003, it
might worth the while trying the pack and go function to see if it
works the same way. you might need to install them from the original cd
as pack and go is not automatically installed with msoffice.