Millisecond Forums

I'm having trouble getting responses to slider items showing up in summary data.  I have created separate sliders for specific items (each on their own survey page), like so...

<survey item_ratings>
/ pages = [1 = rate_item1]
</survey>

<surveypage rate_item1>
/ caption = "Please rate how positive or negative the following items are:"
/ questions = [1=item1]
/ finishlabel = "Next"
</surveypage>

<slider item1>
/ caption = "Item 1"
/ labels = ("very negative", "very positive")
/ range = (0, 60)
/ increment = 1
/ showticks = false
/ showtooltips = false
/ required = true
</slider>

Then, in summary data, I request responses to this item, like so...

<summarydata>
/ columns = [slider.item1.response]
</summarydata>

I am running the Monkey to ensure my summarydata is recording properly.  I am getting values for all of my other columns, such as likert responses, but the slider.item1.response column remains blank.  Any sense on what I'm doing wrong here?