PHP as CGI only executed by request from LAN

Hello,

today I've installed PHP 5.0.3 as CGI and want to use it with Apache
1.3.27 on Suse 8.2.
PHP 4 is installed as module, too.
PHP5 should only be used in defined directories, otherwise PHP4. That
works, but my problem is the following:
When I open my phpinfo-testpage from an other computer in my LAN, the
PHP-script is correctly executed by PHP5. But when someone from the
internet opens that page, PHP is not executed, so the sourcecode is
the content of the requested file.
The PHP4-Module is working as it should.

My configuration for that in my httpd.conf is the following:

# PHP5
<Directory /usr/local/php5/bin/>
Options +ExecCGI +FollowSymLinks
AllowOverride None
</Directory>

ScriptAlias /php5bin /usr/local/php5/bin/

<Directory /srv/www/htdocs/php5>
Action php5-cgi /php5bin/php
AddHandler php5-cgi .php
</Directory>

Greets,
Nils