Google App Engine: Update model definitons?

Question

I recently updated one of my models by adding a db.ListProperty():

class DependencyArcTail(db.Model):
    courses = db.ListProperty(db.Key)

    ''' newly added '''
    forwardLinks = db.ListProperty(db.Key)

However, I can't seem to get this to be reflected in the SDK dashboard. I cleared the datastore and reloaded it. Then I ran the procedures that create the DependencyArcTail objects. However, forwardLinks still doesn't show up as an attribute in the SDK dashboard. What's happening?