BigP, when you mentioned that the "media server" function wasn't allowing you to watch SW Desp. on the PS3, were you referring to such programs as "PS3 Media Server" or "TVersity"?

If you have a router, not only should you be able to use either of those programs to stream the video to the PS3, but you can also copy it over to the PS3's hard drive.

On the other hand, if the problem is indeed in the file's format (which I doubt is the case), then a program like "Handbrake" can convert the file into something the PS3 can recognize.