The widget title stored in a space doesn't change

[vohtaski]

Description:
When we use the opensocial api to change the title of
our Iframe widget, then the title displayed next to the "toggle" button changes,
but the title stored in space (accessed through the opensocial api) doesn't change.

How to reproduce:

1. Go to http://course.onlinesjtu.com/mod/widgetspace/view.php?id=16494
2. Notice the title of the second widget (baidu). We changed it by clicking on "change content"
   (using "gadgets.window.setTitle(title);").
3. Use the rating widget (the first widget) to rate the second widget. The title retrieved by the
   rating widget (via "osapi.apps.get({contextId: appId}).execute(function(app) {app.displayName})")
   is the former, original title.

Expected behaviour:
The name shown in the rating gadget should be the current name of the gadget.

Additional info:
A similar problem arises when widgets are removed/replaced on a space. Before the change, the rating widget
retrieves the correct name. After the change (e.g. by replacing widget 2 with another widget), the rating widget
still shows the old name.