You have some old spry code on the page that could be causing issues.
Remove this on lines 574-578
<script type="text/javascript">
<!--
var spryselect1 = new Spry.Widget.ValidationSelect("spryselect1", {validateOn:["blur"]});
//-->
</script>
You can also remove the spry includes on lines 205-210
<link href="../SpryAssets/SpryValidationTextField.css" rel="stylesheet" type="text/css" />
<link href="../SpryAssets/SpryValidationTextarea.css" rel="stylesheet" type="text/css" />
<link href="../SpryAssets/SpryValidationSelect.css" rel="stylesheet" type="text/css" />
<script src="../SpryAssets/SpryValidationTextField.js" type="text/javascript"></script>
<script src="../SpryAssets/SpryValidationTextarea.js" type="text/javascript"></script>
<script src="../SpryAssets/SpryValidationSelect.js" type="text/javascript"></script>
You aren't using them and it is probably interfering with the validation you are using now.