lamp架构 我安装完php后，，apache启动不起来

加载了php模块后，apeche 就启动不起来？ 为什么？
[root@localhost php-5.2.14]# /usr/local/apache2/bin/apachectl restart
httpd: Syntax error on line 119 of /usr/local/apache2/conf/httpd.conf: Cannot load /usr/local/apache2/modules/libphp5.so into server: /usr/local/apache2/modules/libphp5.so: symbol xmlTextReaderSetup, version LIBXML2_2.6.28 not defined in file libxml2.so.2 with link time reference

我查看了下下面的模块都是存在的；
[root@localhost php-5.2.14]# locate libxml2.so.2
/usr/lib/libxml2.so.2
/usr/lib/libxml2.so.2.6.26
/usr/lib64/libxml2.so.2
/usr/lib64/libxml2.so.2.6.26
/usr/src/lamp/libxml2-2.7.7/.libs/libxml2.so.2
/usr/src/lamp/libxml2-2.7.7/.libs/libxml2.so.2.7.7
[root@localhost php-5.2.14]# ll /usr/local/libxml2/lib/libxml2.so
libxml2.so        libxml2.so.2      libxml2.so.2.7.7
[root@localhost php-5.2.14]# ll /usr/local/libxml2/lib/libxml2.so.2
lrwxrwxrwx 1 root root 16 01-17 15:24 /usr/local/libxml2/lib/libxml2.so.2 -> libxml2.so.2.7.7

那位大哥知道是什么回事吗？ 小弟不胜感激。。。急！

    httpd.conf中添加 php5_module        libphp5.so