"page not found" error but panels page exists

I can reproduce the described behaviour on the German site when accessing the contact form as anonymous user.

Additional potential candidates:

• Path alias cache (from Pressflow 6.16) - disabling has no noticable effect to this issue
• CSS Gzip (6.x-1.3) - deactivating/disabling has no noticable effect to this issue
• JavaScript Aggregator (6.x-1.4) - deactivating/disabling has no noticable effect to this issue
• Memacache - ?
• Mollom - ?

Boost: Deactivating and clicking "Clear Boost's Database & File Cache" at /admin/settings/performance/boost has the following results:

• neither the "page not found" error message
• nor the confirmation message (!) is displayed

However, the contact message is being sent (and logged in watchdog).

Changing issue queue to 'Boost' which seems to be the most probable candidate.

Hm... all I know so far is that the aggregated CSS file (eg ./sites/default/files/css/css_c8422c178f9cc122e3ed52d4febeb504.css) seems to cause "page not found" errors even if the page exists. I really have no idea how a CSS file could cause this, and I don't understand why the watchdog "Location" record (.../css_c8422c178f9cc122e3ed52d4febeb504.css) is hyperlinked to a panel page respectively the website's front page.

Ah yes, and I can say for sure that I'm experiencing similar issues on different websites, all runing Boost. As far as I can reproduce this "page not found" behaviour it vanishes as soon as I disable Boost (plus clicking "Clear Boost's Database & File Cache").

Example generated boost rules:

  ### BOOST START ###
  AddDefaultCharset utf-8
  FileETag All
  <FilesMatch "\.((html))$">
    <IfModule mod_expires.c>
      ExpiresDefault A1
    </IfModule>
    <IfModule mod_headers.c>
      Header set Expires "Sun, 19 Nov 1978 05:00:00 GMT"
      Header set Cache-Control "no-store, no-cache, must-revalidate, post-check=0, pre-check=0"
    </IfModule>
  </FilesMatch>
  <IfModule mod_mime.c>
    AddCharset utf-8 .html
    AddCharset utf-8 .css
    AddCharset utf-8 .js
  </IfModule>
  <FilesMatch "\.(html)$">
    ForceType text/html
  </FilesMatch>
  <FilesMatch "\.(js)$">
    ForceType text/javascript
  </FilesMatch>
  <FilesMatch "\.(css)$">
    ForceType text/css
  </FilesMatch>

  # NORMAL - Cached css & js files
  RewriteCond %{DOCUMENT_ROOT}/cache/perm/%{SERVER_NAME}%{REQUEST_URI}_\.css -s
  RewriteRule .* cache/perm/%{SERVER_NAME}%{REQUEST_URI}_\.css [L,QSA,T=text/css]
  RewriteCond %{DOCUMENT_ROOT}/cache/perm/%{SERVER_NAME}%{REQUEST_URI}_\.js -s
  RewriteRule .* cache/perm/%{SERVER_NAME}%{REQUEST_URI}_\.js [L,QSA,T=text/javascript]

  # Caching for anonymous users
  # Skip boost IF not get request OR uri has wrong dir OR cookie is set OR request came from this server OR https request
  RewriteCond %{REQUEST_METHOD} !^(GET|HEAD)$ [OR]
  RewriteCond %{REQUEST_URI} (^/(admin|cache|misc|modules|sites|system|openid|themes|node/add))|(/(comment/reply|edit|user|user/(login|password|register))$) [OR]
  RewriteCond %{HTTP:Pragma} no-cache [OR]
  RewriteCond %{HTTP:Cache-Control} no-cache [OR]
  RewriteCond %{HTTPS} on [OR]
  RewriteCond %{HTTP_COOKIE} DRUPAL_UID
  RewriteRule .* - [S=1]

  # NORMAL
  RewriteCond %{DOCUMENT_ROOT}/cache/normal/%{SERVER_NAME}%{REQUEST_URI}_%{QUERY_STRING}\.html -s
  RewriteRule .* cache/normal/%{SERVER_NAME}%{REQUEST_URI}_%{QUERY_STRING}\.html [L,T=text/html]

  ### BOOST END ###

If it helps I can try to document the Boost settings from ./admin/settings/performance/boost or anything else that might be necessary. This applies to boost 6.x-1.x-dev from 2010-Jun-12.

Thanks & greetings,
-asb

Updated to the latest dev release, but the watchdog log is still flooded with messages like this:

# drush ws
 Id      Date          Severity  Type            Message
 147583  17/Jul 13:12  warning   page not found  frontpage
 147582  17/Jul 13:12  warning   page not found  frontpage
 147581  17/Jul 13:12  warning   page not found  frontpage
 147580  17/Jul 13:11  warning   page not found  frontpage
 147579  17/Jul 13:11  warning   page not found  frontpage
 147578  17/Jul 13:11  warning   page not found  frontpage
 147577  17/Jul 13:11  warning   page not found  frontpage
 147576  17/Jul 13:11  warning   page not found  frontpage
 147575  17/Jul 13:11  warning   page not found  frontpage
 147574  17/Jul 13:10  warning   page not found  frontpage
...

So, is there any news on this issue, or could I do something to help tracking this down?

Thanks & greetings, -asb

That sounds quite reasonable. But how do I verify this?

At least I can get rid of this problem by disabling the Boost cache, so it's definitely related to boost somehow. However, disabling Boost creates a whole bunch of other problems (i.e. severe server load ;), so it's no usable solution.

I'm still getting these errors with the latest dev release of 'boost', and I don't have the faintest idea what is causing this. Anyone?