i open page of "Legacy of a Thousand Suns" in IE8 today but flash object is not load i try clean tempolary but still not load, page debug is show this...

Webpage error details

User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0)
Timestamp: Fri, 29 Mar 2013 0020 UTC

Message: 'JSON' is undefined
Line: 3
Char: 5
Code: 0
URI: http://armorgames.com/agi_frame.html?message={"callee":"setIframeDimensions","args":[{"height":4585},"comments"]}

i using Windows XP sp3 with lastes Flash player plugin
but on firefox and chrome is can open it.
how can i do?