If you create a dijit.form.Select with a lot of items, it will become slow and render through the end of the page (no scrollbars). Instead, use a dijit.form.ComboBox; it is fast and renders correctly. It doesn’t necessarily need a itemstore, a HTML <select> list works perfectly fine. Just add dojoType=’dijit.form.ComboBox’ and you’re done.
Note: this doesn’t work if you have a ‘value’ in your <option> tags. The ComboBox always takes the label as value.