Dear Cactus and David,
I think I've found it!
David suggested to update php5-cgi.
By accident there were Updates from contribs allso for php5-cgi.
Apr 04 10:30:57 Updated: php5-cgi-mysql.i386 5.2.8-1.el4.sme
Apr 04 10:30:57 Updated: php5-cgi-ldap.i386 5.2.8-1.el4.sme
Apr 04 10:30:59 Updated: proftpd.i386 1.3.2-1.el4.rf
Apr 04 10:31:00 Updated: php5-cgi-imap.i386 5.2.8-1.el4.sme
Apr 04 10:31:00 Updated: php5-cgi-xmlrpc.i386 5.2.8-1.el4.sme
Apr 04 10:31:01 Updated: php5-cgi.i386 5.2.8-1.el4.sme
Apr 04 10:31:03 Updated: php5-cgi-pear.i386 5.2.8-1.el4.sme
But then the configuration didn't work anymore.
I started searching on contribs.org for a solution and found the new howto for installing php5-cgi.
http://wiki.contribs.org/PHP5There I followed the instructions and installed smeserver-php5-cgi.noarch 1.0-2.el4.sme.
I removed the old custom templates and made a new one with the new parameters.
<Directory /opt/egroupware/html/rpc.php>
AddHandler php5-cgi .php
Action php5-cgi /php5-cgi/php-cgi
</Directory>
Now I can sync without filling the logs...
I am going to install this allso with my other customer to see if I got it right...
But I have a good feeling...
Have a nice weekend and thanx for your help!
Grtz Simon