The file /space/websites/CompanySites/example.com/robots.txt does _not_ exist
I request http://example.com/robots.txt, and I get a 404 instead of the default content

config:
======

in the main section:
--------------------
RewriteEngine on                                                                                                                                               
RewriteCond %{LA-U:REQUEST_FILENAME} !-f                                                                                                                       
RewriteRule ^/robots\.txt$ /etc/apache2/config/robots.txt.default [L]                                                                                          

in the vhost:
-------------
RewriteEngine On                                                                                                                                       
RewriteOptions Inherit                                                                                                                                 
                                                                                                                                                           
DocumentRoot /space/websites/CompanySites/example.com

rewritelog:
===========
/initial] (2) init rewrite engine with requested uri /robots.txt                                                                                               
/initial] (3) applying pattern '^/robots\.txt$' to uri '/robots.txt'                                                                                           
/subreq] (2) init rewrite engine with requested uri /robots.txt                                                                                                
/subreq] (3) applying pattern '^/robots\.txt$' to uri '/robots.txt'                                                                                            
/subreq] (4) RewriteCond: input='' pattern='!-f' => matched                                                                                                    
/subreq] (2) rewrite '/robots.txt' -> '/etc/apache2/config/robots.txt.default'                                                                                 
/subreq] (2) local path result: /etc/apache2/config/robots.txt.default                                                                                         
/subreq] (1) go-ahead with /etc/apache2/config/robots.txt.default [OK]                                                                                         
/initial] (5) lookahead: path=/robots.txt var=REQUEST_FILENAME -> val=/etc/apache2/config/robots.txt.default                                                   
/initial] (4) RewriteCond: input='/etc/apache2/config/robots.txt.default' pattern='!-f' => not-matched                                                         
/initial] (1) pass through /robots.txt