I've looked through a lot of posts regarding this, but it seems like none of the proposed solutions have fixed it for me.

Installed SWFTools 6x3beta5 on most recent drupal 6. Player for each JW and FlowPlayer3 appear, but the video doesn't play. The video was successfully converted, and I can see the files.

For FlowPlayer3, I get the common "200" netstream error (though the path points to the original, not the converted FLV file). JW Player (5) doesn't seem to return an error. Just hangs.