CiviMail settings dont work in 4.1

No matter what you put as your settings in civicrm/admin/mail?reset=1, only 1 cron job runs at a time. The rest exit with "Returning early, since max number of cronjobs running". After further investigation I found that in CRM/Mailing/BAO/Mailing.php, in the processQueue function, the values in $config are wrong.

My settings are 3 mailerJobsMax and 5000 mailerJobSize, but $config->mailerJobsMax, $config->mailerJobSize, and $config->mailerJobSize are both 0.

$config is getting loaded like this:

$config =& CRM_Core_Config::singleton();

But if I force the cache to get reloaded by running this (in the singleton function of CRM/Core/Config.php):

self::$_singleton = new CRM_Core_Config;
self::$_singleton->_initialize( $loadFromDB );

It returns $config with the correct values.

However, even when I set mailerJobsMax to 3 it ended up running 8 processes at the same time during a test mailing. So something else might be wrong here too.