Problem with CGI scripts apparently caused by mod_php4

Hi, I have Apache 1.3.27 and mod_php4 4.2.3 installed on a FreeBSD 4.6.2 machine. PHP works fine. However, I also need to be able to execute CGI scripts. When I try to use printenv (simple shell script that outputs the environment variables) it returns a "500 Internal Server Error" and the Apache error log gives the error of "Premature end of headers". If I comment out the LoadModule and AddModule lines in httpd.conf for PHP, it works. Has anyone seen this before? Thanks. -- Stuart