After updating to Drupal 7.36, many strange problems began to occur. I finally chased it down to the fact that four of my node types were being disabled upon a cache clear. These four node types (bundles) could no longer be viewed in Admin -> Structure -> Content Types. Organic Groups failed since one of the disabled node types was my "Group" node type.
Specifically, it is the Issue
isset($type_object->base) && $type_object->base != 'node content'
and replacing it with
is what causes four of my node types to be disabled.
These four node types have
$type_object->custom contains 0
$_node_types->types[$type_db]) is empty
With, that triggers the disabling of the node type.
Whether this is a result of some flaw in my node types which was not previously trapped or not is beyond my knowledge.