Whether you stick to Atkins or switch to PP, you might try changing the kinds of things you eat--if you have the "Life Plan" version of PP, look into the stricter versions... Dilitante and .. I forget the name but the more paleo version--switching to more basic, natural foods (i.e., no grains, dairy, processed stuff), can make a difference.
Also, make sure you're getting adequate protein and water--maybe try eliminating any artificial sweetners... caffeine can do weird things to some people.
And another completely wacko idea might be to "cycle" a little and see if that breaks things up--nothing major, mind you, but say increase your carbs to eat more veggies and some berries for a couple of days and then go back to your current levels (upping to include grains or legumes would probably be a mistake, though).
Just some thoughts. Personally, I prefer PP myself--a cheaper version of the more purist approach, actually (cheaper in that I can't afford free range meats and all organic veggies and such! but the general idea of what our bodies are more designed to eat being more... compatible?).
ymmv... heck, my mileage varies depending on city versus highway