memory errors

I randomly seem to be getting an out of cache memory error. Has anyone had this issue before. I know there is a setting in settings.php, and I added to that last night. But I am still getting this error randomly. Is there another place that cache settings can be adjusted to stop this?

I am reporting some findings that I hope will help others who decide to try any access control module currently available to Drupal 5.1 or earlier.