I took Malarone in Botswana last year and didn't notice any ill effects or mosquitoes for that matter. Malarone is probably the best anti malarial right now but is also very toxic. I won't take it again. I think wearing long pants, using a spray and staying inside at sunset is probably just as good as taking Malarone.
On a side note, my safari guide in Botswana had lived and worked in Africa his whole life and never had malaria. A little common sense goes a long way.