Easy UI slider step not working as expected

Question

I have this code

<td width="70%">
    <input 
        class="easyui-slider" 
        name="dis" 
        value="5" 
        style="width: 150px" 
        data-options="min:5,max:35,precision:0,step:10,rule: [5,'|',15,'|',25,'|',35], onSlideEnd: function( value ){ $('#someform').submit(); } ">
</td>

and want the user to be able to select only 5, 15, 25, 35.

The problem is that it does not step correctly. After moving the slider the next position it arrives to is 10 instead of 15, then 20 instead of 25, so on... as can be seen in this image. So it looks like it applies the step of 10 but not starting with 5 but starting with 10 !

What is wrong with my code?