I am following the “Basic Usage” example.  I am using the variant wherein I specifically create a <span data-for=”id_of_validated_control”> for each field. In  this case, I have two fields, the first being "Name", the second being "Code".

“Name” and “Code” each have a ‘k-invalid-msg’ span.  Now let’s say I blank out the second field ‘Code’ first.  It’s get “Code is required” message.  So far so good.  Now I put a value in Code, then go to the field above it – “Name” – blank it out, and blur.  I expect the <span> next to "Name" to get a message, but what happens is that “Name is required” displays in the span adjacent to “Code” field, becauseat the moment I tab out of the "Name" field, the <span data-for=”name” class=”k-invalid-msg”/> is removed from the DOM, and Code’s <span> is the one populated.

I have tried several approaches.  The first approach is to declare my own <span data-for="name_of_validated_input" class="k-invalid-msg></span> after each <input> that has the "required" attribute.  I also tried not declaring my own <span>'s, and applying a validationMessage="xxx is required" to each <input> that has the "required" attribute.

Here is one of the <input> controls with an explicit <span>.  Note that this is copied from Chrome "inspect element" which is adding the ="" to required. 

<div class="form-FieldOuter" id="view-FieldBox1" style="display:block;">
<label for="view-FieldBox1CodeInput" class="form-label" style="overflow:hidden;">Code</label>
<input type="text" class="form-control" id="view-FieldBox1CodeInput" data-bind="value: Code" required="" validationmessage="Code is required.">
<span class="k-invalid-msg" data-for="view-FieldBox1CodeInput"></span>
</div>


And a couple of notes/comments:
1. In my program's html output, the attribute doesn't have a value, it looks like <input id="x" name="x" required validationmessage="blah blah"/> 
2. I've tried also assigning the name attribute.  But I see from other forum post that data-for relates to the 'id' attribute and not the 'name' attribute, so I think my use above should be correct in that regard.  (see: http://www.kendoui.com/forums/framework/validation/is-there-a-way-to-control-the-position-of-validation-messages.aspx , where it says To force it to use specific place for its hint, place a span with data-for="your_input_id" and class="k-invalid-msg", so that the Validator can recognize and use it )
3. I observe that data-role="validator" is being applied to the <div> that contains my form and all of the validated <input> and their <span> elements.
4. Using kendo.web.js from version 2012.1.322 Full-license not minified.

        [Authorize]
        [HttpPost]
        public String AddFile(int Id, IEnumerable<HttpPostedFileBase> attachments)
        {
            
            Response.ContentType = "text/plain"; 
            return   @"{""status"": 0, ""data"": [{""DocumentId"": ""5""}]}"; 
 
        }

        $("#attachments").kendoUpload({
            async: {
                saveUrl: saveURL,
                removeUrl: removeURL,
                autoUpload: true
            },
            upload: attachOnUpload,
            success: attachOnSuccess,
            error: attachOnError
        });


function attachOnUpload(e) {
 
        e.data = { Id: '@Model.Id' }
 
    }
 
    function attachOnSuccess(e) {
         
        var hiddenField = $("#DocumentId");
        hiddenField.val(e.DocumentId);
        
 
    }
    function attachOnError(e) {
        debugger;
	//always fires no matter what is returned from controller

    }

$("#testing_listview").kendoMobileListView({ ...