Please describe the problem:
A file filer is set to a FileChooserButton. The first time the FileChooserButton is clicked, the filter is there and works. The second time, the filter is gone. This can be confirmed by the FileChooser.list_filters() method, or by the look of the FileChooser dialog.

Expected behavior: The file filter is persistent.
Observed behavior: The file filter disappears after the first activation of the FileChooserButton.

Unknown if this is caused by the "button" or by the FileChooser.

Attached: small demonstration example.
Tested with Ubuntu 8.10 and python-gtk2 version 2.13.0ubuntu8.

Steps to reproduce:
Either run the python program at http://launchpadlibrarian.net/25995141/fcb.py
or

1. Create a gtk.Window, a gtk.FileChooserButton and a gtk.FileFilter.
2. Add a pattern to the FileFilter.
3. Add the filter to the button, and the button to the Window.
4. Start gtk.main()
5. Click the button, which opens a dialog.
6. Observe the Filter being active
7. Select a file and click Open.
8. Click the Button again.
9. Observe that there is no filter; all files in the current directory are visible.


Actual results:
The file filter is active the first time the dialog is used, but not at later times.

Expected results:
The filter should be persistent.

Does this happen every time?
Yes. At least with my installation; Ubuntu 8.10, pygtk (python-gtk2) 2.13.0-0ubuntu8

Other information:
See also bug report at: https://bugs.launchpad.net/ubuntu/+source/pygtk/+bug/367285