Compiled both PHP 3.0.2. and Apache 1.3.1 with
-R option (as told by perl -V). Execing a php file like
 
dl ("./calendar.so");
echo jdmonthname (1, 3);

makes Apache SIGSEGV immediately and closing connection
without sending anything, and just saying child exit 11
in error_log.

However, when execingon commandline:

> php -ftest.php

no problems occur, and the monthname is printed.