Some WMV Files Stream Some Don't

I have WMP9 on Mac OS 10.3.4. iBook 1.2ghz 768m ram.

I have noticed on a particular website article that most
of the posted wmv files will start to play then about 20-
30s into playing the movie stops. Some files stream all
the way through fine. If I download the problem files they
play fine from my hard drive so I suspect the streaming
functionality is the issue.

The website article with videos is at

http://www.rcgroups.com/links/index.php?id=4492

It's a family safe website for RC model airplanes.

The "Vendor demo flights part 1 of 3" is the first example
of this issue. The first two Vendors wmv files stream OK.

I have cable modem so the bandwidth should be enough to
stream. I've tried playing around with the buffer in
preferences and have deleted the pref file but it doesn't
help.

Thanks,

Kelvin