I have been noticing error jquery.js messages coming from IE8 on all sites using D7. Some sites actually stop you from logging in.
Webpage error details
User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; SLCC1; .NET CLR 2.0.50727; Media Center PC 5.0; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Zune 4.0; OfficeLiveConnector.1.5; OfficeLivePatch.1.3)
Timestamp: Wed, 23 Jun 2010 14:44:54 UTC
Message: Invalid argument.
Line: 1061
Char: 4
Code: 0
URI: http://couples2connect.com/plugins/jquery/jquery.js