Problem playing "Video Clip" files. Like some game trailers I downloaded.

[Zero Plasma]

Video's that say there file type is "Video Clip" play odd on my computer.
Some will freeze right on the first frame, others a dozen or so seconds after it starts.
Whats going on?

Also this is in any all the video players I have that even play it, WMP 10, PowerDVD, and NeroShowtime.