I have a similar application, but I'm not able to bind to the UI dropdown list. The step allows selection by Index, Text or Value, but the Step Properties does not show a property for Bindings, as would be the case if the field were a simple text field.
Here's the HTML for the control..
<div class="ms-crm-Inline-Edit ms-crm-Inline-OptionSet noScroll ms-crm-Inline-HideByZeroHeight" style="display: none;">
<select id="new_preferredlanguage_i" class="ms-crm-SelectBox ms-crm-Inline-OptionSet-AutoOpen ms-crm-Inline-HideByZeroHeight-Ie7" attrname="new_preferredlanguage" defaultselected="100000000" attrpriv="7" title="" tabindex="-1" aria-labelledby="new_preferredlanguage_c new_preferredlanguage_w" size="3" style="height: 48px;" controlmode="normal">
<option title=""></option>
<option value="100000000" title="English">English</option>
<option value="100000001" title="French">French</option>
</select>
Your help would be appreciated.
Thanks,
dan