I am getting this error, maybe your IE8 doesn't have Jquery installed...
Webpage error details
User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; InfoPath.2; .NET4.0C)
Timestamp: Fri, 7 Jun 2013 23:38:32 UTC
Message: Could not get the fontWeight property. Invalid argument.
getting multiple errors in one of your js scripts cb_core.js
Could not get the fontWeight property. Invalid argument.