Thinking About Short Stories

I just read a short story that I think was sabotaged by too many characters, too many separate scenes, too much complexity. The writing was good though so I waded through. But the ending didn't turn it around. The story was more like a blueprint for an eventual novel than a short story to me.

When I studied writing, the professor said that he felt three or four characters was the most there should be in a short story. He also felt it should play out in as few scenes as possible. I seem to have taken that to heart because most of my stories are sparsely populated. "Scrapping", for instance, in an issue of PANK, has three characters and basically three scenes. "Mermaids" in OFF THE RECORD: AT THE MOVIES has five characters but only two scenes. "How to Launder a Shirt" is basically a monologue about three people.. "Undetectable" in PULP INK 2 has four characters but only three really figure in. In other words, in a short story, I don't think you have time to develop many characters and it confuses the reader to try and keep track of too many.

What do you think? I know in the right hands a short story could work with a dozen characters but in average hands, how many is too many characters, settings, scenes?

Perhaps I am under-populating my stories and I shouldn't have listened to that guy.

And here is another question. In a short story, how specific do you like a locale to be? Would you rather have a writer say. 'he's moving up north." Or pinpoint it in a state, "he's moving up to Ipswich."