FLV playback progressive download query

I’m using the FLV Playback component to play FLV files on several web pages. The files on each page range from 15 to 30MB in size. I was under the impression that with progressive FLV Playback, the SWF started playing the file when only a small portion of it had downloaded; however, in this case, the entire FLV seems to be downloading as there is a sizeable delay between the play button being clicked and the FLV starting. When it does play I am able to scrub straight to the end of the movie, which again seems to indicate that it has downloaded in its entirety. I only want a part of it to download before the user can view the start - can anyone tell me where I’m going wrong?