try the code bellow, it is supposed to select option
C0, but empty option was select.
maybe v1.4 consider empty value equals 0, but it is wrong!
<form id="ff" method="post">
<table cellpadding="5">
<tr>
<td>Name:</td>
<td><input class="easyui-textbox" type="text" name="name" data-options="required:true"></input></td>
</tr>
<tr>
<td>Code:</td>
<td><select class="easyui-combobox" name="code">
<option></option>
<option value="0">C0</option>
<option value="1">C1</option>
<option value="2">C2</option>
</select></td>
</tr>
</table>
</form>
<script>
function loadLocal(){
$('#ff').form('load',{
name:'myname',
code:0
});
}
</script>