half-working : player seems to crash

To begin with, thanks a lot, travist, for all your work and support. This flashvideo module seems awesome and I will make it work completely on my web site. Here's my problem :
on a page type node, with [video] and [thumbnail] tags in, I do have the thumbnail of the video, but no video, although, when the page gets loaded, there's a quick window (kind of a pop-up, sort of) that appear and immediately disappear, like something trying to be loaded, but failing and crashing, (is there any log files somewhere I could check ?). I feel like it's from the player,...
using drupal 6.4 on Gentoo. I followed the "Flash Video in Drupal 5: A complete multimedia tutorial" : the flashvideo module is installed and set in drupal with no error. I got the player dashPlayer.swf, renamed in Player.swf. It resides in /drupal/sites/default/files. Page type node is enabled. Original Directory field is set with "original_videos" and Output Directory field with "output_videos", from the FFMPEG settings, in the node type page. So /drupal/sites/default/files/original_videos and /drupal/sites/default/files/output_videos have been created when I uploaded a video. The actually do contain video files (.wmv), produced from the module. I did not create a a Content Template, but a page, and everything seems tuned fine (video import field, "Attach new file:"...)
I tried : put the player in /drupal/files, like mentioned in http://www.travistidwell.com/node/284, with no results. Since original_videos and output_videos directories were created on the fly in /drupal/sites/default/files/, I figured out that the player had to be in /drupal/sites/default/files/ as well.... What did I miss ?