If I make a wiki page with the source:

<div id="MyQuery" />
<script>
new LABKEY.QueryWebPart({
        renderTo: 'MyQuery',
        schemaName: 'core',
        queryName: 'users',
        buttonBar: {
            items: []
        }
    });
</script>

Then I'd expect that I don't get any buttons. But I do -- I get:
Grid Views
Reports
Charts
Insert
Delete
Export
Print
Paging

But if I change the items line to:
items: [{}]

Then I don't get any buttons. Obviously, I am not in need of a fix, but maybe I can prevent someone else from spending 30 minutes figuring this out.

-Will