Ever since I upgraded to version 5.0.2.1 Premier Edition of Norton 360, and had it installed by Norton's own professional, I have encountered the same problem when I first fire up my computer and start using ie 9.0.8112.16421.
The first thing I do when I open ie is click on Identity Safe. I get asked to put in my password, and if I enter it incorrectly, I get a second try. However, whether or not I enter it incorrectly the first time, as soon as I enter the correct password (first, or second attempt) a message box appears saying "Internet Explorer has stopped working Windows is checking for a solution to the problem ..." and then a second message box saying "Internet Explorer has stopped working A problem