Recently, I’ve noticed there is a category/ tag name “Contests” added to the title of all of my pages.
I’ve checked the “Tagline” under “Settings” >> “General” of course, it hasn’t changed.
This is what’s in header.php and I have never touched it at all:
<title><?php wp_title(''); ?><?php if(wp_title('', false)) { echo ' :'; } ?> <?php bloginfo('name'); ?> </title>
I’ve found the cause.
All in one SEO Pack plugin 1.6.14.5 is guilty (perhaps it’s not guilty by itself but also due to the multisite setup of my site and other plugins I’ve just installed conflicting it). Disabling the plugin resolve the problem immediately. I’m upgrading it and will use an alternative if it doesn’t work out. Thanks @LeaCohen for pointing me to the right redirection.
Updates
Instead of deactivating the plugin, disabling the auto-rewrite title in settings of the plugin is sufficient.
At the same time, just FYI, All-in-one SEO Pack plugin version 1.6.13.8 works just fine for WordPress multisite 3.4.2. I can no claims about the possible conflicts between this and any other WordPress plugins