Hi,
I'm currently experiencing a bug related to the Bug "PHPBB3-11215", that should have been fixed years ago! But still isn't fixed properly! In the support forums i got no response on the question how to disable that symfony shit (yes it is shit/crap/whatever you can call it, I don't care about readable url!!!!! Either copy&paste, use search or use google)

If you install phpbb in a sub directory styles may get broken (invalid path to css files) when an invalid file or directory is used in the url (e.g. www.domain.com/dir/to/phpbb/app.php/path/to/non/existent/file.html)
This issue seemes to get fixed after clearing the cache but after a random amount of time the error reoccurs.
Also:
If an extension tries to show the forumlist (e.g. Board3 Portal) all image-paths are pointing to nonexistent files (in this case app.php/portal/images/[...] while it should be app.php/portal/../images/[...] or www.domain.com/dir/to/phpbb/images/[...]).

This behaviour can be seen here: (how it looks like(note the missing forum icons)) http://www.iskariot.info/IskariotWebsite/phpbb3/app.php/portal
What it should look like:
http://www.iskariot.info/IskariotWebsite/phpbb3/index.php

Both issues are related to symfony (readable links).
(OFFTOPIC) that is in my opinion the worst idea some dev (of symfony) ever had and I'd like to see an option (in phpbb) disable this "feature" (aka bloatware/bug), because it creates more bugs than it solves.
Back to (TOPIC)
The symfony links make browser search for files like this "app.php/images/..." instead of "images/..." resulting in wrong paths