manifestcreative, thank you very much for those notes. It helped me figure out where to start looking for a clue regarding the why, as well as provided a solution for the others in this thread to solve.
Here's a snippet from the register_post_type codex page regarding the capability_type field, which defaults to 'post':
"(string or array) (optional) The string to use to build the read, edit, and delete capabilities. May be passed as an array to allow for alternative plurals when using this argument as a base to construct the capabilities, e.g. array('story', 'stories') the first array element will be used for the singular capabilities and the second array element for the plural capabilities, this is instead of the auto generated version if no array is given which would be "storys". By default the capability_type is used as a base to construct capabilities. It seems that
map_meta_cap needs to be set to true, to make this work."
That last sentence is what caught my eye the most, because in this latest release we added the registering of the map_meta_cap parameter by default and set to true. It defaults to false normally.
Now, I don't fully understand why this would cause the "Pages" list to disappear, would love to hear explanation if anyone knows why. However, that's the closest thing I can find in relation to this topic, for stuff that had changed since the 0.8.0 release.