It is a known issue and related to a Norton update or so it appears at this time .. Anyway, go to Internet Options through the Control Panel and then to the Advanced Tab. Click on the "Reset" button in the bottom right hand corner. This basically reinstalls IE and solves the problem.
http://community.norton.com/t5/Norto...E8/td-p/406950
Submitted via EggHeadCafe
ASP.NET JSON Cookies and Excel
http://www.eggheadcafe.com/tutorials...and-excel.aspx