WebkitError when loading a new video (only safari)

Hi

I’m building a video portfolio site and whenever I load a new video when the old video is still loading (buffering) I get a “Operation could not be completed. (WebkitErrorDomain error 203.)”.

I only get this error when I try to load a new video when the playing video is only partly downloaded… and only in Safari (OS X). Here is the link: http://www.mvbroekhuizen.com/preview.html

It’s not a critical error, but still I would like to remove it before finishing up this project…
I’ve searched quite some time but couldn’t find any fix… so maybe here someone has had the same errors?
Is there a way to stop the buffering or loading before loading a new file?