It only happens if you have the newest Internet Explorer installed (IE > Version eight).
If you watch the stream on an html-page, you can force the new IE to act like IE8 by adding:
<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE8" />
in the <head> </head>area.
cheers
btw: this is the mjpg-stream: http://xxx.xx.xxx.xx/video/mjpg.cgi