angularjs formName.$dirty does not work with IE9. I am using 1.2.17.build164 version.
here is the form that I am testing, I am not getting the form dirty!!! printed in the page. Same code works fine with firefox and chrome.
<form name="formName" ng-submit="doSubmit();">
<input type="text" name="firstName"/>
<span ng-show="formName.$dirty">form dirty!!!</span>
</form>
you don't have model field on the input box:-)
<form name="formName" ng-submit="doSubmit();">
<input type="text" name="firstName" ng-model="hello"/>
<span ng-show="formName.$dirty">form dirty!!!</span>
</form>