I've taken a look at the code and the problem is that using that method is working with an onclick event. You're looking for a change event. What you have to do is use a different spry method that will execute onchange (on the changing of the selected index of the menu) such as this:
<div spry:region="ds1">
<select spry:repeatchildren="ds1" onchange="ds1.setCurrentRow(this.value)">
<option value="{ds_RowID}">{title}</option>
</select>
</div>
Use the ds_RowID as the value of the dropdown option field and then have the menu change the current row of the spry data set to the selected value.
Abraham
