Module Issues

Brand new installation of FreePBX 2.10 on top of Asterisk 1.10, running with CentOS 6. Most of the installation went smoothly, but there are certain modules that are showing they need “System Admin” and “PHP Component Zend Guard Loader” to install. I tried installing “System Admin” and got the below error. Anyone know the fix? Thanks.

System Admin cannot be installed:
PHP Component Zend Guard Loader is required but missing from you PHP installation.
File /usr/sbin/incrond must exist.
Please try again after the dependencies have been installed.