Change plugin to inactive then active produces error

Go into Settings -> Plugin List and set songs Inactive. OK the list.
Go back into the Plugin List and set songs active again.

The following appears on the console:

Traceback (most recent call last):
  File "/home/jonathan/openlp/trunk/openlp/core/ui/pluginform.py", line 137, in onStatusComboBoxChanged
    self.pluginListWidget.currentItem().setText(
AttributeError: 'NoneType' object has no attribute 'setText'