After adding a new property from within the
property editor, this property is not shown. 

Steps to reproduce: Create a new properties file
(from the built-in template). Add one property
(e.g. key1) using the "New Property" button. The
new property is displayed in the editor. Add
another property (e.g. key2). The property is not
displayed. When you save the file and open it via
"Edit" (instead of Open) the two keys are present.

The following file is created when following the
above steps:
----------------- file starts here ------------------
# Sample ResourceBundle properties file
key1=value1

key2=value2
----------------- file ends here ------------------

Unless I edit the file manually, no new property
will be displayed by the properties editor