Log Hours UI does not display role or start date for ad hoc activities

To reproduce:

• click "Log Volunteer Hours"
• click "Add Volunteer" to add a row to the table
• supply values and save the form
• load the form again by clicking "Log Volunteer Hours"

All the data you entered will be displayed back to you except for Role and Start Date.

Originally reported here: http://forum.civicrm.org/index.php/topic,33744.0.html.