I use 0.5.4 swfplay player to watch youtube video.
I was build on debian sid with './configure --enable-ffmpeg --disable-gstreamer'
The problem is that the top/left corner of the video is in the center (see the attachment), and bottom/right is cropped.
Created attachment 13131 [details]
That's been an issue with the new youtube player - in particular when watching Youtube videos embedded on other pages.
And that has been fixed in git.