Ran into an issue with IE8 and using the JQuery validation framework. Basically what was happening was that the validation framework was kicking in and identifying the errors (correct) but the form was still getting submitted to the server. (Incorrect!) Anyway after some investigation I found that it was the console.log statements in the javascript code that was causing the issues. As I was using the developer toolbar provided with IE I wasn't seeing the issue this is because the console object gets created when you open the developer toolbar duh! So if you are getting some weird behaviour check that you don't have any console statements in you Javascript files.