I’ve resolved this. Root cause was not RTFM.
PHP version 5.2.4 or greater
And I had 5.2.17. Now with 5.3.3 installed all is well. Sorry for the stupid.
Some additional information:
WP install 3.5.1
Plugins installed:
AddThis Social Bookmarking Widget
Akismet
Captcha
Configure SMTP
Jetpack by WordPress.com
jQuery Archive List Widget
Ultimate tag cloud widget
Ultimate TinyMCE
Updater
Wordfence Security
Wordpress Popular Posts
WordPress SEO
Host details:
CentOS 5.9
Apache 2.2.22
PHP 5.2.17
