I'm not familiar with united streaming, but you might contact them and ask
if they've done any codec changes or anything lately.
Here are some troubleshooting things you can try.
http://www.echosvoice.com/tshoot_video2.htm
One test used frequently is to go to Start|Run and type mplay32.exe and run
the video in that. If it runs there, it should run in PPT. You might try
your old ASF files and the new ASF files and see if they both run.
Now, I don't know a whole lot about ASF, but when I go to File|Open in
mplay32.exe, I see ASF listed under Direct Show. So I would check the direct
show settings on your video card and see if changing those helps. Updating
your video card driver might also help.

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Echo [MS PPT MVP] http://www.echosvoice.com
What's new in PPT 2007? http://www.echosvoice.com/2007.htm
Fixing PowerPoint Annoyances http://www.oreilly.com/catalog/powerpointannoy/
PPTLive! Sept 17-20, 2006 http://www.pptlive.com
>A video from united streaming, the file type is .asf these have been
> inserted before. Using the typical insert, movie, movie from file method.
[quoted text clipped - 17 lines]
>> > suggest a
>> > way to fix this? The appropriate file types are being used.