I also came across that problem. By default settings, do you mean that you have it save as name.ext? (Under Frame/Animation Ext). If not, try switching it to name.#.ext, the start and finish frames should be open for editing, and from there you can edit which frames you want to render.
"All the world's a stage, and all the Men and Women merely players: they have their exits, and their entrances, and one man in his time plays many parts."
-William Shakespeare