Trying module and get "PHP MySQLi support not enabled"

We are trying out this module and are running into an error right away. While trying to login via https, we receive a Drupal error:

PHP MySQLi support not enabled
We were unable to use the MySQLi database because the MySQLi extension for PHP is not installed. Check your PHP.ini to see how you can enable it.

For more help, see the Installation and upgrading handbook. If you are unsure what these terms mean you should probably contact your hosting provider.

Very odd as the mysqli driver is in use and working properly. Server specs are as follows:

PHP version = 5.2.4 cgi
Webserver = Apache/1.3.33 (Unix)
Database = mysqli 5.0.51-log, lock.system=flock

We did set the $base_url in settings.php per that point in the install instructions, the http version, no trailing slash.

Any suggestions?