Javascript error on Video chat

I got the following javascript error in my video chat box. It appears to work ok, but wonder why the error is there in IE?

Webpage error details

User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 2.0.50727; InfoPath.2; .NET CLR 1.1.4322; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)
Timestamp: Wed, 24 Feb 2010 00:51:36 UTC

Message: 'null' is null or not an object
Line: 71
Char: 1
Code: 0
URI: http://www.XXX.com/modules/boonex/messenger/popup.php?rspId=16

Yes, this problem is mainly for IE.

Is there any way to fix it? Or any reason to fix it?

I can't even open the chatroom in IE8 if I am in Vista, but works perfectly with IE8 using xp pro

no problem here in ie7 or ie8  on vista or windows 7..