Can anyone offer help re Apache2 and phpicalendar?

["Darcy Parker (Home)" <ddparker@yourlink.ca>]

Good day all,

   I have setup an internal websever using Apache2 and I have added 
phpicalendar.  The problem I am having is getting the remote 
phpicalendar to update using the calendar plug-in under mozila thunderbird.

It is a standard debian install, the websever is working,  I can see the 
calendar, but I can't update it remotely.  I think I do have WEBDav 
installed as well.  I have called the site myhomesite (internal only).  
I just copied the 000-default site to myhomesite and modified it to 
point to the directory with the  webfiles and  phpicalendar locations.

myhome:/etc/apache2/sites-enabled# ls
default-ssl  myhomesite
myhome:/etc/apache2/sites-enabled#

myhome:/etc/apache2/sites-enabled# cat myhomesite
NameVirtualHost *:80
<VirtualHost *:80>
       ServerAdmin webmaster@myhome.net

       DocumentRoot /var/www/
       <Directory />
               Options FollowSymLinks
               AllowOverride None
       </Directory>
       <Directory /var/www/>
               Options Indexes FollowSymLinks MultiViews
               AllowOverride None
               Order allow,deny
               allow from all
               # This directive allows us to have apache2's default 
start page
               # in /apache2-default/, but still have / go to the right 
place
               RedirectMatch ^/$ /myhomesite/
       </Directory>

       <Directory "/var/www/myhomesite/">
               Options Indexes FollowSymLinks MultiViews
               AllowOverride None
               AuthUserFile /var/www/myhomesite/.htpasswd
               AuthType Basic
               AuthName "Authorized Users Only!"
               Require valid-user
        </Directory>

       Alias /phpicalendar/calendars/publish.ical.php 
/usr/share/phpicalendar/calendars/publish.ical.php
       Alias /phpicalendar/calendars/publish.mozilla.php 
/usr/share/phpicalendar/calendars/publish.mozilla.php
       Alias /phpicalendar/calendars /var/lib/phpicalendar/calendars
       Alias /phpicalendar /usr/share/phpicalendar

       <Directory "/usr/share/phpicalendar/">
                DAV On
                Options Indexes FollowSymLinks MultiViews
                AllowOverride None
                AuthUserFile /var/www/myhomesite/.htpasswd
                AuthType Basic
                AuthName "Authorized Users Only!"
                Require valid-user
        </Directory>

       #You will probably want to restrict publishing to authenticated 
users,
       # if you enable $phpicalendar_publishing in
       # /etc/phpicalendar/config.inc.php
       <Location /phpicalendar/calendars>
               <LimitExcept GET POST OPTIONS PROPFIND>
                       Order deny,allow
                       Deny from all
                       AuthType Kerberos
                       AuthName foobar
                       Require valid-user
                       Satisfy any
               </LimitExcept>
       </Location>


       ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
       <Directory "/usr/lib/cgi-bin">
               AllowOverride None
               Options ExecCGI -MultiViews +SymLinksIfOwnerMatch
               Order allow,deny
               Allow from all
       </Directory>

       ErrorLog /var/log/apache2/error.log

       # Possible values include: debug, info, notice, warn, error, crit,
       # alert, emerg.
       LogLevel warn

       CustomLog /var/log/apache2/access.log combined
       ServerSignature On

       Alias /icons/ "/usr/share/apache2/icons/"
       <Directory "/usr/share/apache2/icons">
           Options Indexes MultiViews
           AllowOverride None
           Order allow,deny
           Allow from all
       </Directory>

   Alias /doc/ "/usr/share/doc/"
   <Directory "/usr/share/doc/">
       Options Indexes MultiViews FollowSymLinks
       AllowOverride None
       Order deny,allow
       Deny from all
       Allow from 127.0.0.0/255.0.0.0 ::1/128
   </Directory>

</VirtualHost>

Here is the listing of my mods-enabled showing webdav is OK.
myhome:/etc/apache2/mods-enabled# ls
actions.load  dav_fs.conf  dav.load      mime_magic.conf  php4.conf  
rewrite.load  ssl.load      userdir.load
cgi.load      dav_fs.load  deflate.load  mime_magic.load  php4.load  
ssl.conf      userdir.conf
myhome:/etc/apache2/mods-enabled#

The error I get when I try to publish to the calendar file is

"Publishing the calendar file failed.
Status Code: 500: Internal server error"

I am new to linux (newbie) and I have probally missed something simple.

Thanx for any help for other users.

Darcy