Just FYI, for all those who use XO hosting... here's the fix they gave us:
In the wp-settings.php file, replace
// Fix for IIS, which doesn't set REQUEST_URI
if ( empty( $_SERVER['REQUEST_URI'] ) ) {
// IIS Mod-Rewrite
if (isset($_SERVER['HTTP_X_ORIGINAL_URL'])) {
$_SERVER['REQUEST_URI'] = $_SERVER['HTTP_X_ORIGINAL_URL'];
}
// IIS Isapi_Rewrite
else if (isset($_SERVER['HTTP_X_REWRITE_URL'])) {
$_SERVER['REQUEST_URI'] = $_SERVER['HTTP_X_REWRITE_URL'];
}
else
{
// Some IIS + PHP configurations puts the script-name in the path-info (No need to append it twice)
if ( isset($_SERVER['PATH_INFO']) ) {
if ( $_SERVER['PATH_INFO'] == $_SERVER['SCRIPT_NAME'] )
$_SERVER['REQUEST_URI'] = $_SERVER['PATH_INFO'];
else
$_SERVER['REQUEST_URI'] = $_SERVER['SCRIPT_NAME'] . $_SERVER['PATH_INFO'];
}
// Append the query string if it exists and isn't null
if (isset($_SERVER['QUERY_STRING']) && !empty($_SERVER['QUERY_STRING'])) {
$_SERVER['REQUEST_URI'] .= '?' . $_SERVER['QUERY_STRING'];
}
}
}
// Fix for PHP as CGI hosts that set SCRIPT_FILENAME to something ending in php.cgi for all requests
if ( isset($_SERVER['SCRIPT_FILENAME']) && ( strpos($_SERVER['SCRIPT_FILENAME'], 'php.cgi') == strlen($_SERVER['SCRIPT_FILENAME']) - 7 ) )
$_SERVER['SCRIPT_FILENAME'] = $_SERVER['PATH_TRANSLATED'];
// Fix for Dreamhost and other PHP as CGI hosts
if (strpos($_SERVER['SCRIPT_NAME'], 'php.cgi') !== false)
unset($_SERVER['PATH_INFO']);
with...
if(isset($_SERVER['QUERY_STRING']) && !empty($_SERVER['QUERY_STRING'])) {
$_SERVER['REQUEST_URI'] = $_SERVER['PHP_SELF'] . '?' . $_SERVER['QUERY_STRING'];
} else {
$_SERVER['REQUEST_URI'] = $_SERVER['PHP_SELF'];
}