small square appearing in center of video

Hi,
I have video streaming from a flash media server.
Some people are seeing a small square appear in the center.
This square sometimes has soft video, sometimes its white, may even be from the wrong frame.
check out this example.
http://www.gasolicious.com/flashstuf...e_square_2.jpg

any ideas?
I have put up a test file with various info about the file displayed.
bitrate, dynamic switching info etc. Also I moved the buffering mc to top right, off the video, just in case that was causing a problem.

http://www.gasolicious.com/OrangeUpload/index.html

Even if you do not know what might cause it I would appreciate some more testing. Drop by watch a video or 2 and let me know if you see the square and what the displays say if you do.

Thanks
mark

Added info,
it seems the little square does not appear when the buffering movie clip is removed from on top of the video.
So you will not see the square at link above anymore.
Buffering mc is on top of the video, I set its visible property when video is buffering or not.
Any ideas on how to fix this issue?

change the depth?
addChild/remove?

mark