Images are not shown in admin panel

[anonymous]

While showing the admin panel the preview images are not shown. While checking the url trac shows the following error.

AttributeError: 'PageListModule' object has no attribute 'get_htdocs_dirs'

However, the project plan images look fine. It's just a problem within the admin panel.

trac.log shows the following error:

2010-02-12 00:23:11,237 Trac[main] ERROR: Internal Server Error:
Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/trac/web/main.py", line 450, in _dispatch_request
    dispatcher.dispatch(req)
  File "/usr/lib/python2.5/site-packages/trac/web/main.py", line 206, in dispatch
    resp = chosen_handler.process_request(req)
  File "/usr/lib/python2.5/site-packages/trac/web/chrome.py", line 398, in process_request
    in provider.get_htdocs_dirs() if dir[0] == prefix]:
AttributeError: 'PageListModule' object has no attribute 'get_htdocs_dirs'

[anonymous]

Using the following configuration:

System Information:
Trac: 	0.11.6
Python: 	2.5.4 (r254:67916, Nov 19 2009, 22:30:11) [GCC 4.3.4]
setuptools: 	0.6
SQLite: 	3.6.21
pysqlite: 	2.5.5
Genshi: 	0.5.1
mod_python: 	3.3.1

[Andreas]

Well, it seems to be depending on the PageListPlugin?. As we do not use this plugin within ours, the problem seems not to be caused by ProjectPlanPlugin.