True, when copy/pasting from a word processor, you have to go back through and remove the paragraph returns between each line. The editor automatically adds space after each return, so the typical (Enter Enter) one makes with a word processor is too much in the editor.
Also, make sure you are using <p> rather than <div> (look at the lower right of the editor box (or source) and it will tell you). <div> uses a slightly larger spacing.
Us SHIFT ENTER to do this:
--->closer
But that doesn't work quite as well in the story viewers. Spacing has been slightly off for quite some time.
Good Luck!