Symfony2找不到GET ofiler或GET nfigurator的路由

I have just installed Symfony2 and created my bundle. I removed the Acme demo bundle and tested my new route "/" which worked fine.

I then went to config.php and followed the link to _configurator and get the above route error. I also get the same error when trying to load _profiler.

Here is my route file:

asf_core_homepage:
    pattern:  /
    defaults: { _controller: ASFCoreBundle:Home:index }

And the Symfony routing_dev file:

_wdt:
    resource: "@WebProfilerBundle/Resources/config/routing/wdt.xml"
    prefix:   /_wdt

_profiler:
    resource: "@WebProfilerBundle/Resources/config/routing/profiler.xml"
    prefix:   /_profiler

_configurator:
    resource: "@SensioDistributionBundle/Resources/config/routing/webconfigurator.xml"
    prefix:   /_configurator

_main:
    resource: routing.yml

Any ideas why this is happening?

EDIT

I have narrowed it down and it looks like it has nothing to do with symfony. I have it installed in a subfolder of root so I use htaccess to rewrite all requests from /forum to /forum/web

RewriteRule forum/(.*) /forum/web/$1 [L]

If I point the browser to /forum/app_dev.php it works fine. the error comes from /forum/app_dev.php/_configurator

But if I skip the rewrite rule and use /forum/web/app_dev.php/_configurator it works fine.