Magento system log 2015-07-14T14:48:34+00:00 ERR (3): Warning: Mage_Core_Model_App::dispatchEvent(): Node no longer exists

Question

We are receiving the following error over and over and completely filling up the system.log file: 2015-07-14T14:48:34+00:00 ERR (3): Warning: Mage_Core_Model_App::dispatchEvent(): Node no longer exists in /chroot/home/website/html/app/code/core/Mage/Core/Model/App.php on line 1281

This is line 1281 to 1287. How do I fix this? I'm sure what this means.

                foreach ($eventConfig->observers->children() as $obsName=>$obsConfig) {
                $observers[$obsName] = array(
                    'type'  => (string)$obsConfig->type,
                    'model' => $obsConfig->class ? (string)$obsConfig->class : $obsConfig->getClassName(),
                    'method'=> (string)$obsConfig->method,
                    'args'  => (array)$obsConfig->args,
                );

we have flushed cache, re indexed, re run and disable compiler.