Is N360 compatable with IE9?
Full Support will be only available when the final version will be out, but during the beta tests N360 version 5 worked fine with the IE9 beta. I did not tested the RC yet, but will do it soon.
I am using IE 9 RC with my NIS 2011 and there have not been any compatibility problems so far. Everything is working, even the Toolbar. I'm not sure if this helps, but I would assume it would be the same for Norton 360.
Please read the information provided in the following Symantec KB: