Thanks for the quick reply Ivan.
I don't believe #1 is the case, because none of my users have multiple roles.
I just broke inheritance and found this behavior to be kind of interesting.
By default, the page that I could get to WITHOUT logging in had 'Allow' checked for 'Everyone'. However, it DID NOT have this before breaking inheritance.
Also when breaking inheritance, the page that gave me the 'Page Not Served' error did not have any boxes checked.
Could it be possible that these pages were moved from different page groups, and that somehow it carried permission with them? I'm just speculating on why these pages could show the same permission, yet default differently when inheritance was broken.
Either way, i know that I can break inheritance to get around any issues that I find, so it's not high priority.