Evidently their Flash code is not designed for Flash 10 compatibility. You can try uninstalling Flash and installing an older version, which may result in decreased performance, compatibility, and security, or notify them that they need to check and update their Flash animation.
( e.g. http://www.albinoblacksheep.com/flash/dubdub )
I have Internet Explorer 7 and have Adobe Flash player 10 installed (though I've had this problem with previous versions too).