using a image upload form doesn't work on IE9 but works on Chrome and firefox (MVC3)
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I've created a form for creating user to my ASP.NET MVC3 Application using the following line

        @using(Html.BeginForm(MVC.Profile.Register(), FormMethod.Post, new { enctype = "multipart/form-data", encoding="multipart/form-data" })) {
           <fieldset>
                <div> 
                    <h1>Your Picture</h1>
                    <div> 
                        <img data-changepicture id="userImgPicture" src="@Model.photoUrl" />
                        <input id="user-picture" type="file" name="@Html.GetFieldNameFor(m => m.userPicture)" />
                    </div>     
                </div>
            <div class="saveButtonArea">
                <input class="bigButtonHighlight" type="submit" value="@(Model.finishRegister ? "Save" : "Confirm")" />
            </div>
           </fieldset>
         }

Using image comes to my action trough a HttpPostedFileWrapper (inside a model) but in IE its value is always null, but in chrome or firefox it works just fine.

Any thoughts or suggestions?