Apparently it's true that Herman Cain has befriended this woman for well over a decade. That's not exactly a casual acquaintance, so it wouldn't be all that out of the ordinary for him to take the time to return her call, even if he is busy with his campaign.
Candidates are real people like you and I, and they talk to all sorts of people all day, every day. At least the down to earth ones do. I'm not so sure about self-important elitists like Romney and Newt.
As for the claim that Herman took calls from this woman at 2:00 AM, this is the first I've seen of it. Source?
I will try and find the source for you...I read it several times earlier today...
NationalReview.com..in the original story by Katrina Trinko..link on the homepage..she quotes the FOX reporter who broke the story as seeing texts/calls "as early (late?) as 4:26am..."